Rod Heikell's very informal site on sailing around bits of the world and an eclectic collection of things nautical or nearly so.

Practical Boat Stuff 2: Electronics & Navigation


These pages have a motley collection of practical stuff for boats. It all comes from hands-on stuff on our boats that gets tested in the real cruising world and on those wet salty passages where you find out what works and what doesn't.

KISS   keep it simple stupid


If you wander around the boatshow as I did this year, you could be forgiven for thinking that somewhere between the good old days and the glittering arrays on the stands at the boat show that we seem to be missing the point about going sailing and cruising. The basics have got mixed up with the toys that have a by-line like Ďessential for every cruising boatí or Ďdonít leave port without oneí. Its all for your convenience and you would be a fool not to have one on board.

There is a grand complication between the salesmanís patter about the integrated, PC or Mac compatible, talking to the instruments, gee-gaw that you must have and that simple old fashioned concept of capturing the wind in those white things and gliding over the sea to a destination.

In fact most of the equipment we need is low-tech and it needs to be reliable. We run all sorts of complicated gizmos in Skylax: a couple of chart-plotters, integrated instruments and autopilot, radar, lap-top navigation and routing software, all sorts of stuff. The nub of it all is whether you need to continually be repairing all this stuff or whether you keep cruising and repair or replace a piece of equipment when you can. I see all sorts of boats stuck in a harbours around the world waiting for a spare part or replacement gear. In fact most of what we need to keep these sailing dinosaurs going is simple basic stuff and a lot of what enhances cruising is low-tech or at best intermediate technology.

KISS. Below are some simple things that make your cruising more enjoyable and also some caveats on things we use.

GPS & cartography

Chart plotters


Laptops on board

WIFI on board

Paper stuff

Polarised views



GPS & Cartography

GPS and thee

This is a slightly modified version of an article from 2000 published in Germany but not in a UK magazine. I have modified some bits to allow for the removal of SA and the introduction of WAAS and EGNOS, but in all other respects nothing has changed.

In brief, we have an amazing system for position finding but nothing accurate enough to plot it on.


For the 1999-2000 Imray Mediterranean Almanac we decided to delete the astro ephemeris. For the previous two editions (spanning four years) I had been monitoring the reply cards on which one question was: Do you think the Almanac should include astro ephemeris? On the last count the Ďnoí vote was winning, although only just at around 60% NO to 40% YES. My guess is that of the Ďyesí group, only a fraction of them actually use the ephemeris and most of them want it there for the comfort factor as a back-up. Yet if you had taken the survey less than ten years ago I suspect you would have had somewhere around a 90% Ďyesí vote. No Almanac editor would have thought twice about including astro ephemeris. Today we find the majority of Almanacs do not include it.

The decline in the use of astro ephemeris to determine position can be attributed directly to the availability of GPS receivers and the chips and software which have made them easier to use. To some extent Loran-C and SATNAV helped to keep the sextant in itís box, but it was GPS that relegated many sextants to the most inaccessible locker on board and kept it there.

GPS was developed for the American military. The original acronym NAVSTAR more properly describes how it works. NAVSTAR is NAVigation System by Time and Ranging. GPS simply means Global Positioning System which tells us little. In fact the way GPS works is simple and familiar to anyone who has done some coastal navigation. If we know the position and distance of an object then our own position can be plotted on a line from that known object. Plot three known objects and distances and we have a relatively accurate position fix. In practice three satellites distances and positions are plotted because of the inaccuracy of receiver clocks and degrading effects from the signals passing through the ionosphere. The resulting cocked hat gives a consistent accuracy of ` 20 metres for 95% of the time. However the American military decided that this degree of accuracy should only be available to the military and so it degraded the signal to civilian users by Selective Availability (SA) to give an accuracy of ` 100 metres for 95% of the time. SA was removed on midnight May 1st 2000 so that civilian users now had an accuracy of `20 metres or so.

In 2002 WAAS (Wide Area Augmentation System) was introduced in the USA with initially just two stations operating. Since then the number of stations has increased and GPS accuracy has been improved to `5 metres, though less than 3 metres is often given. In fact independent tests have shown over a 48 hour period that accuracy is typically 3.2 metres horizontally and 6 metres vertically for 95% of observations with a range of 8 metres horizontally and 15.5 metres vertically. However you look at the figures this is a stunning degree of accuracy. In Europe the EGNOS system (European Geostationary Navigation Overlay Service), similar to and amazingly compatible with WAAS, was introduced in 2005. In Asia, but only in Japan at the moment, MSAS (Multi-functional Satellite Augmentation System) is under development and this to is compatible with WAAS and EGNOS.

All these systems rely on ground stations in known locations receiving satellite GPS positions, correcting them from the known position of the ground station, and then via relay stations sending the corrections back to the satellite and then down to a WAAS/EGNOS/MSAS enabled GPS receiver. Brilliant.

Modern GPS receivers are multi-channel and can receive at least twelve signals at any one time and decode them to determine a position. The speed at which a GPS receiver can do a cold start and produce a position is now around 30 seconds. The ease with which we retrieve data has been simplified by software that enables us to scroll through pages and pick out how we want to view the data. From the stream of position data we get speed over the ground, course heading in true and magnetic, distance off course from a waypoint, and a graphic display of our course. A GPS receiver can be interfaced to electronic charts or a chartplotter and we can plug in waypoints for a route and watch our boat sailing along on the chart like some arcade amusement game. In the early 90ís if someone had said you could buy an instrument for just over £100 that would do all this you would have politely changed the subject and declined to buy him another drink.

So is everything calm with fair winds and a few digital beeps as you make landfall. Iím afraid not. There are still sea monsters out there.

Problem No. 1   Knowing your position is not much use if you donít have accurate charts to plot it on.

With GPS we know what our position is to within 5-10 metres on the earthís surface. What we do not have are charts of the earthís surface which are accurate to this degree. Most of the charts we use were surveyed in the 19th century using celestial methods to determine latitude and longitude. Given the difficulties that many charts were surveyed under including bad weather conditions and hostile natives ashore, with just leadlines and sextants for equipment, the resulting charts are amazingly accurate. Many of them are beautifully detailed affairs and given the difficulties of standing in a small pinnace and taking sights to determine position, they are a tribute to the men who made them.

Section of a chart by Beaufort 1812. A work of art but not necessarily GPS accurate. This chart was still the stock chart until the 1980's.

That said, the charts could not possibly be consistently accurate compared to the repeatable accuracy of modern position finding equipment and so it is not surprising that in some areas there are errors of up to one nautical mile and more.

The British Hydrographic Office divides the problem of accuracy into three parts.

1        Modern surveys by the Royal Navy using DGPS have a standard of around plus or minus 13 metres accuracy and as such have an accuracy compatible to GPS accuracy Ė not surprising when the data is derived using DGPS. (Using SDGPS the accuracy is now probably around `5 metres.)

2        Paper and ARCS charts assembled from various datum sources have a relative accuracy dependant on how recent and how accurate the last surveys were and this is now shown on Admiralty charts with the source diagram of the surveys. Here the worst case scenario should be taken and in many cases this will include a portion of a 19th century survey. It is difficult to know what this relative inaccuracy is, but be warned that some relative inaccuracies of up to 3 miles exist between the charted position and the actual GPS position. While relative inaccuracies will be eliminated by future surveys in the developed countries, this is unlikely to be the case for less developed countries where hydrographic departments are under-funded and have relatively unsophisticated surveying equipment.

3        The last problem is purely a cartographic one of scale. Small scale charts will appear more accurate than large scale charts. Ergo, a small scale chart has the appearance of accuracy although it cannot be used close to land and dangers to navigation.      

So depending on the source of the last survey there can be inaccuracies of up to 1 mile and in worst case scenarios probably a relative inaccuracy of up to 3 miles for some old surveys. The French hydrographic department will only guarantee itís charts to 1000 metres in the northern hemisphere and 2000 metres in the southern hemisphere according to a report by Bateaux magazine.

 Most charts have been amended and corrected with more recent survey information where it is available and satellite imaging has been used to get the spatial relationships right in some cases, but in the end we are still left with amended 19th century charts for many parts of the world. This is sometimes disguised by the modern appearance of charts which look like new surveys because they have new colour schemes and have been metricated, but which are still for the most part old surveys patched up with some modern information.

 One of the principal problems has been to get the lat and long accurate to a datum standard which has now become WGS84, equivalent to, but perversely called ETRF89 (European Terrestrial Reference Frame 1989). This is all likely to be scrapped with a new datum model being developed called EGM06. For most old surveys there can be considerable errors of longitude. Mostly this has been sorted out by simply adjusting longitude to account for errors or alternatively supplying a correction factor on the chart of ` so many minutes of lat or long so it can be used with GPS. This is basically an ad hoc solution and does not account for relative errors on the chart itself. For example if Cape Death was found to have an error of 0.3 minutes E and the longitude on the chart was adjusted by 0.3 minutes W to correct it, that could mean that Cape Fear ten miles down the coast would be in error by 0.3 minutes W because itís original position was accurate. What happens in the end is some juggling by the cartographer to come to an average solution.

 The point of all this is that many charts, especially from countries with ill equipped and under-funded hydrographic departments, will not have been resurveyed with modern equipment to unravel these errors. We end up in the position of having an accurate position finding system with GPS, but inaccurate charts to plot the information on.


What this means to craft navigating in these waters is that some circle of error (COE) around the boat must be used when close to dangers to navigation. Just what COE you use is difficult to sort out. In the Red Sea I used a minimum COE of one mile, but extended it to 1Ĺ miles off places like Eritrea and Yemen when it seemed that there were large discrepancies. In the eastern Mediterranean you can probably get by with a COE of less than half a mile but not less than 0.25 of a mile in places. In well charted waters such as the UK and western Europe errors are much smaller and in some cases negligible. In parts of the Pacific there are larger errors and the COE would probably have to be two miles.

 Plot coming into Kastellorizon 2006 using latest electronic chart. Actual course is nearly a quarter of a mile NW down into the harbour - and no, we didn't have wheels on.

All of the above applies equally to electronic charts. Electronic charts are simply digitised versions of paper charts and so contain all the errors of paper charts. This explains why when you are close to land that the little boat on your plotter is happily toddling across a headland or a reef or whatever. Vectorised charts can be invisibly seamed together and this may give the appearance of a new chart, but seamless charts are purely the result of digital magic and not the result of new information.


Problem 2   Chart Datum

When you draw a chart you must determine where the lat and long lines go. In the early days of charting the surveyor would use a defined datum for his area or if one did not exist, he would define his own. This has resulted in there being hundreds of chart datums around the world. GPS requires that there be one datum system for the world and this has been agreed as WGS84 datum (though see above). This is the default setting on a GPS unit, but if you are plotting a position on a chart referenced to another datum then you will need to select that datum on the GPS. Most, but not all charts, will have the datum it is referenced to on the chart itself. Most GPS units will have around 100-150 of the most common datums in their memory and it is simply a matter of choosing the correct datum from a list on the menu so you can plot the GPS position directly onto the chart.

 Some charts do not have a datum source mentioned and in many cases for out of the way places the datum is simply not known. In Europe and the USA a different datum reference to WGS84 will mean a difference of perhaps 100-300 metres for lat and long and commonly less. But in other areas it can mean a difference of up to one mile. It makes sense to always check the chart datum and if it is not WGS84 then select the appropriate datum from the list on your GPS. If no datum is listed on a chart then you need to be very careful about plotting positions on that chart and use a large circle of error.


 Problem 3   Waypoints

While I was in Florida I overheard a conversation in Bluewater Books that left me worrying a bit about some newcomers to sailing. The man wanted a pilot for the Bahamas and he wanted it to have waypoints and pilotage instruction so that he could just put the waypoints in his GPS and go there. The sales assistant tried to help him out with the several pilots available, but no, he wanted something simpler than that with simple instructions on getting from one waypoint to another. He didnít want to have to do any reading or to look at detailed charts. Anyone who has looked at a chart of the Bahamas has to wonder whether he was going to make it past the first reef.

 Waypoints are a useful function on GPS that has increased the certainty of navigation a hundredfold. But they can also be a trap for anyone not paying attention to their navigation. Waypoints are frequently given for a position inside an anchorage or harbour, for a buoy marking a shoal or reef, and for the entrance to a passage. Even worse is the trend to producing a booklet of waypoints that gives only a brief indication of where the waypoint is and no pilotage instructions regarding the approach to the waypoint.

 Now what I am going to say sounds so obvious that I hesitate to say it, but it appears that it is not quite so obvious to some people out there or that some navigators are being mesmerised by the wonders of GPS.

 If you have a waypoint then the approach to it is critical. You will be proceeding in a straight line from your point of origin and if there are dangers to navigation, usually a reef or shoal water, around that waypoint, then you need to approach it on a course which keeps you clear of those dangers. This is often not the course you will be on from your point of origin to the waypoint. I know itís obvious, but if it is so obvious why do yachts keep piling up on reefs and going aground because they have ignored this obvious fact.

 The problem is further compounded by waypoints distributed verbally or over the VHF to other yachts without sufficient definition of where the waypoint is. So you get a message on the radio or are told in a bar that a waypoint of XYZ will take you safely into an anchorage. Someone at anchor in the anchorage has taken the waypoint and gallantly distributed it to everyone. But if you do not have any information on what bearing to take into the anchorage this could lead you straight onto a reef or shoal water in the approaches. Likewise if you have a waypoint for the entrance to a passage then approaching it on the wrong bearing could put you in danger and you could run up on the rocks.

 It would be easy to say that this all happened to newcomers getting afloat with their brand new GPS. Sadly it is occurring to some who have been afloat for a while and who have started to blindly trust the efficacy of GPS for making difficult approaches. To an extent this is understandable when you have made nine approaches spot on with GPS homing right into the waypoint. It is also understandable when you arrive off an anchorage at night and decide that with a waypoint you can safely enter rather than hanging around all night until an entry can be made in the morning. It is the tenth time where it doesnít pan out that requires us to be ever vigilant and exercise proper seamanship in the approach to an anchorage or harbour.

 There is one further problem with waypoints and that is there origin. If you donít know where it came from then you wonít know how accurate it is. In my pilots I always try to give the origin of a waypoint. Frequently it is the light at the entrance to a harbour or near an anchorage. For the Mediterranean the lat and long of lights has been gradually corrected over the years to presumably a lat and long based on WGS84 although this is not always stated by the relevant hydrographic department. In any case a volume of the List of Lights for an area is a handy guide to waypoints as long as they are used cautiously. In other cases I have verified lat and longs, my own and others, for waypoints to WGS84 and this will be stated as such. In some cases an unverified lat and long, either from the chart or other sources, may be given and such lat and longs should be used with some care. No matter how accurate the waypoint is you should be piloting yourself in using visual fixes to locate where you are.


Problem 4   Why am I such a Luddite?

Simple answer: I am not. There is no way I would not use GPS and in fact I carry three back-up receivers. As well there are two chartplotters running on board, one at the helm and one below in the chart table and on the lap-tops we have navigation software/routing software/weather/tides etc.


There would be few who would not agree that this one instrument is a revolution in position finding and like ziploc bags and velcro, you wonder how you ever managed without it. It is not just the position finding but the ancillary readouts like an instant magnetic heading and speed over the ground which provide much useful information at the touch of a button. Put in waypoints and you end up correcting your course when it is off by an ľ of a mile. I remember a time when if you arrived within a couple of miles of your destination you were well pleased.


So I am not a Luddite. I love my GPS(Ďs). But I am conscious that the appearance of accuracy can lull us (myself included) into a sense of well-being that can put us in danger. They really do mean it when that message flashes up on the screen to the effect that GPS is an aid to navigation and should not replace all other means of navigation.


When you carry a spare GPS (or two) its a good idea to have a 12V DC plug so you can run it off the ships batteries. On the way across the Atlantic in 2005 our chartplotter (new) failed and Lu modified an old yoghurt pot so the back-up GPS could sit outside and get a signal because the integral aerial didn't receive down below. It also made it easy for the person on watch to keep an eye on things.


(My thanks to G Shimmin at the Geodesy department of the British Hydrographic Office for his help with this article.)


Chart Plotters

From the Skylax blog 24-09-07

Chart plotters

Chart plotters are a useful aid to navigation and previously we had a small Garmin 276 down at the chart table. For this trip I got a Garmin 3006 and a plastic nacelle from ebay so it could be mounted on the binnacle bar. The bar needed to be modified, as did the nacelle (it was for another unit), but overall it looks OK and importantly gives the helmsman something to look at. It was tempting to link it up with everything else, but Iíve had too many electronics go down in the past, even those mounted down below and in several cases only just out of the box. Itís fine for the manufacturer to say he will replace it within warranty, but thatís little help mid-Atlantic and all your waypoints have just disappeared. So Iím going for lots of standalone units without having the instruments, radar, other chart plotter, etc. all interfaced to one another.

A friend on another boat has been without his radar for months. It is piped to the chart plotter display but somehow his software for it has been corrupted . Now thatís fine if you are in the UK near a dealer, but just try to get it fixed in southern Italy or Greece. Heís taking the unit back with him. As for us, just makes me happy to have a standalone unit that is visible from the cockpit (itís mounted on the bulkhead where the chart table is) and not interfaced to everything else. The wetware we were all born with is pretty good at bringing together disparate bits of information and we all need to be aware of that warning that comes up before you are allowed into a display unit: This is an aid to navigation blah blah. And so it is. We need to combine all the information we have, from the plotter, depth sounder, the Mk I eyeball, the chart, the pilots, radar, and cautiously use it to make landfall or approach any of those hard bits above or below water. Iíve just plotted a position of an alleged uncharted rock. Well itís about 30 metres away from a charted rock and you are just plain foolish to believe your electronic chart or plotter is that accurate.

Have a look at the plot below.



From the Skylax blog 30-04-08


On watch you need to keep an eye on any nearby shipping and if it looks a bit iffy then give them a call on VHF to establish their CPA. This always led to conversations like Ďmotor vessel in approximate position da-de-da this is sailing yacht Skylax in position da-da-da on a true course of daa, overí. Sometimes we would get an answer and sometimes not. So when I was back in the UK I bought the simple stand-alone NASA unit and a VHF aerial for Skylax.

We had it fitted in no time and connected up to the GPS below despite the primitive little instruction manual that comes with it. Like most NASA stuff it has itís limitations, but for the price it is a grand little receiver and does what says on the box.

On the trip from Sint Maarten down here to Panama we only used the radar once. The rest of the time the AIS provided sufficient information to establish a CPA and when we did call up, we had that all important handle, THE NAME OF THE SHIP. Over seven days we probably called up half a dozen ships to establish a CPA and they all answered. For other ships, and remember we are on the rhumb line for ships approaching and leaving the Panama Canal and ports in Columbia so there were a fair number around, we had sufficient information from their position, course and speed to establish that they would be well clear of us.

It also has the benefit of drawing very little power compared to the radar that we would normally turn on to establish distance and course relative to us. It has a few little niggles. Lu finds it hard to get used to a N-up read-out compared to head-up. It occasionally gets a bit flustered and loses the GPS signal, though re-booting the GPS plotter usually sorts that out. And it has no on and off switch so Lu installed a little push-pull switch so it can be turned off independently Ė the breaker feeds other instruments as well.

So for £200 I give it full marks and it suits my KISS philosophy keeping all instrument systems separate rather than linked. We could have bought an AIS engine that came up on the Garmin plotter in the cockpit, but that would mean a hardware or software failure there would shut down not just the plotter but the AIS as well. I also installed a separate VHF aerial on the pushpit instead of a splitter to the masthead VHF aerial. This gives us a spare aerial for the VHF should anything happen to the masthead unit and despite not being very high, we have had signals from ship up to 16 miles away, though more commonly it is half this distance.


Laptops on board

From the Skylax blog 12-04-09

 Laptops on board

It seems to make sense and for a while I used a laptop for navigation, backed up of course by paper charts. In the bad old days once you had paid your money for the software you were given a key that sat on the hard drive. In Haiti I innocently decided to defrag the hard drive and when I next booted the software (Kiwitech) up a message came up to email the suppliers for a new key. Not to easy in Haiti in those days. Today this problem seems not to exist anymore, but it may be worth checking before you defrag a hard drive.

My laptop was kept secure on the chart table with Velcro and this was fine except when things got really bumpy and the hard drive protested at all the thumping the boat was taking. This can still be a problem and a lot of modern laptops will flash up a warning about vibration affecting the hard drive. A few laptops have cushioned hard drives that can cope with a boat thumping along in a sea. 

In the end laptop navigation was not for me. Kiwitech was bought by Raymarine and I kept up through several versions of the software now called Raytech. There are a lot of functions on Raytech software and this is part of the problem for me. When I was tired and went below to check things I would need to first find my glasses and then attempt to get the cursor over the button or menu I needed. This can be difficult and in the end I found it easier to use a mouse than the touchpad found on most laptops. Software that has the facility to be configured with a few big buttons, the ones you will likely use when at sea, makes it a lot easier and you can always revert to a lot of smaller buttons and more functions when in harbour planning the trip.

I have to confess that I stopped using a laptop and navigation software when at sea and have become a convert to the chartplotter. Its got less buttons, itís tougher, and its waterproof. We have one at the helm and a small Garmin 276 down at the chart table.

Garmin 3006 at the helm

I still use the laptop and navigation software for some planning, though really I like to get those old fashioned paper charts out and have a good look at where I am going on them. I also use Visual Passage Planner ( ) quite a lot for planning longer passages. We do have one computer we use at sea and that is an older tablet PC (with a cushioned hard drive) that is used with a steam-powered Pactor modem and the SSB to download weather GRIB files and to email our position at sea. Itís quite a compact unit that sits on a shelf next to the chart table and has a touch screen and a rubberised keyboard. I doubt it would be fast enough to run todayís processor and RAM hungry software, but you could conceivably run simple navigation software.

Tablet PC on shelf at the chart table - it's steam-powered but runs plenty fast enough for the Pactor modem and other simple functions like tides. Bought on Ebay for £180.

For more on SSB and Pactor modems and the like go to Lu's Radio Page


WIFI on board

A friend of mine, Jack Marsh in Turkey, showed me this little trick to increase a wi-fi signal. Just take a collander, any old metal collander, and tape a wi-fi receiver dongle in it as shown. Fire up the computer and then put the collander 'dish' out of a hatch and angle it at the aerial broadcasting the signal. In some cases the signal will be bouncing off solid objects like the walls of a building so the angle may not be directly pointed at the aerial. Its cheap and its worth buying a dongle to put in the 'dish' even if your laptop has an aerial (as most of them do) enclosed somewhere around the screen. Thanks Jack.





Update on Wifi

From the Skylax blog 03-01-09

Almost as important as a secure berth or anchorage these days is access to wifi. An increasing number of places broadcast wifi over a marina and an anchorage and although we are not talking the sort of speeds you get from broadband at home, there is usually enough to get email and browse slowly. To some extent it is a matter of picking a time when there are not a lot of other people trying to use the wifi signal Ė that can be early in the morning, at lunchtime or around dinner time, itís a matter of experimenting in the location you are in.

In a marina or especially at anchor one of the problems is to get a good signal and for this you need an external aerial you can poke outside.

The first external aerial I used was simply a USB dongle taped into a colander (thanks for the idea Jack) that acted as a dish to amplify the signal. It works so so.

The second one I got is a Hawking dish aerial that we nick-named Ďmini-Jodrell Bankí. You can get two types. One plugs into the wifi card via a coaxial cable. Most laptops donít have this option. The second plugs into a USB port. You simply install the software and the rest is pretty seamless. What you will need is a USB male/female extension cable so you can park the dish up out of a hatch or somewhere on deck so it has an easier time picking a signal. Jodrell worked just fine but it has a couple of drawbacks.

The first is that it needs to be aimed approximately towards the transmitting aerial. When you are swinging around at anchor this means that signal strength goes up and down and sometimes disappears. The second drawback is that it is not waterproof and the little PCB inside doesnít like to get wet Ė not even moist. Does this sound like the voice of experience? Oh yes, one little tropical shower and Jodrell was dead though he still valiantly tried to light up the LEDís on the front. No amount of drying him off and spraying the insides worked. Jodrell is a dead parrot.

So whatís next? A couple of other boats used an outdoor omni-direction rod aerial. With an extension you can hoist this up on a flag halyard and get better signal strength. You can even further weatherproof it by sticking it in an old plastic water bottle with a bit of silicone around the neck and hang it up that way.

Iíve tracked down a omni-direction outdoor job for a tad over £60 and given the Hawking was around £40 that seems OK. The picture below is from the internet site which majors on bad English but hopefully has a good techy background.

 WiFi Link


Wifi locations Greece to NZ

From Greece to NZ on this trip we got wifi in the following locations. For many of these services you could sign up using Paypal or a credit card and be up and working in no time at all. Only in a few cases was there a conflict or a glitch.


Spain (Almerimar): Via the marina company or from Centrepoint (travel and real estate co.) within the marina. Relatively cheap and reliable service.


Gibraltar: Fairly expensive system in Marina Bay with Yachtconnect. Good signal. Yachtconnect also operate in other Spanish marinas along the coast.


Lanzarote (Puerto Calero): Good system in the marina and reasonably priced.


Cape Verdes (Mindelo): Only in the ĎYacht Clubí restaurant.


Antigua (Jolly Harbour): Good signal and not too expensive by HotHotHotSpot. Also provides services in other islands down the chain (so you can use any credit in other spots): Prickly Bay in Grenada, Admiralty Bay in Bequia, Falmouth Harbour, English Harbour in Antigua, Union Island, Deshaies and Isle de Saintes in Guadeloupe, Portsmouth and Roseau in Dominica.


St Maarten (Lagoon Marina): Reasonable signal and not too expensive.


Panama (PCYC Colon): Cheap wifi but not useable in the anchorage. Patchy in the YC. Sign up in the YC.

Panama (Balboa YC): Free wifi with good signal though moorings are expensive here.


French Polynesia: Iaoranet provides wifi in Nuka Hiva, Rangiroa, Tahiti, Huahine, Raiatea, Tahaa and Bora Bora. Its not cheap but works reasonably well. Another service called Hotspot also operates in French Polynesia.


Tonga (Neiafu): Weak wifi in the anchorage from various bars on the waterfront including the Mermaid (free) and the Aquarium (you pay but it is a better service). Other bars have wifi in the bar/cafť.


NZ: Wifi in Opua Marina. Wifi in Gulf Harbour Marina. Wifi in Westhaven Marina in Auckland.

New Caledonia: Wifi in Noumea but difficult to organise (has to be authorised through a local phone number). Wifi in the MacDonalds near the harbour so ingest some awful food or coffee and connect.

Vanuatu: Wifi in Vila. Internet cafes in Luganville.

Australia: Wifi in Cairns Marlin Marina. Wifi in Cullen Bay Marina, Bayview and Tipperary.

Indonesia: Some internet cafes in larger towns.

Singapore: Wifi in Raffles Marina and RSYC.




Paper stuff

Some basic paper reminders


We make up our own logbooks using the pages reproduced below. Then it's off to the local print shop to get the pages photocopied with the overleaf page on the back so pages are back-to-back, then print off your own cover and get them laminated and then the whole affair is spiral bound. OK so they don't last as well as a properly bound book, but generally they will last a season.

We keep a 3 hour log on board which is filled in on change of watch when on passage. Apart from it being a legal requirement, it can be useful if for any reason all the instruments go down (and they do) so you will at least know where you are from the last log entry. And it makes for interesting reading at a later date - food seems to figure prominently in the comments section. 

 Put the boats name and registration number and any other pertinent details at the top of the page. Use an Excel or other spreadsheet to make up an A4 page or use the tables feature on a word processor.










Course reqd.

COG (Track)

Dist NM





Don't forget to leave a margin on the right hand side of the left hand page and vice versa for the ring binding.






Emergency ...

If something bad should happen, (libations to all the gods that it never does) I have a check card on the bulkhead at the chart table so if I get jittery from the adrenaline pumping through me because something bad has happened (libations to all gods ancient and modern and any others i don't know about) then I can look at the card and at least phonetically spell the name of the boat and then run through the correct procedure. It also has a checklist of the order and type of things to grab should we need to abandon (I promise wonderful libations to all gods the next time I open the finest bottle of wine) ship. I just print it off the computer and then get it laminated at the local stationery shop. The layout I use is below.


HF/VHF Procedure



Sierra    Kilo    Yankee    Lima    Alfa       X-ray

Call sign   MGAY   Mike   Golf   Alfa   Yankee

MMSI   235051169



Mayday         Mayday         Mayday

Skylax   Skylax   Skylax

Mayday Skylax

Give position    (GPS and/or bearing and distance off fixed point or major port)

Brief description of problem: Urgent assistance reqd./POB/over



Pan     Pan     Pan                 and then as above



Emergency Checklist


Launch Liferaft and tie to yacht

Launch inflatable

Panic Bag

Water cans


Food and additional water

Documents/ fishing lines/ torch/ anything useful/ more water




Polarised views

One of the cheapest and best bits of navigation equipment you can buy is a pair of polarised sun-glasses. By this I mean polarised sun-glasses and not any other sort however much they promise in terms of glare reduction, UV protection and style. Polarised plastic is known as a dichromic material and the important thing about it is that it transmits light only in one plane, typically the vertical plane. By cutting out the horizontal plane polarised materials effectively remove one plane of the reflected light on the surface of the sea and this allows us to see transmitted light bouncing off shallow areas such reefs and sandy bottoms. These are all the light blue, green and turquoise colours that identify underwater obstacles.

The value of polarised sunglasses in detecting just where a reef is and where the sandy patch is to drop anchor should not be underestimated. Normal sunglasses just will not do. You can check if your sunglasses are polarised plastic by getting hold of a pair you know are polarised and rotating the lenses of the two through 180ļ. At some point the two lenses together will not transmit light and will effectively go black.

And of course polarised sunglasses help cut down UV radiation which is damaging to your eyes.

Non polarised                                                     Polarised


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