Cruising Communications – Part 2


March 20th, 2024


Equipment, Technical

Written by

Richard Farrington

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By Richard. Posted on March 20th, 2024 in Equipment, Technical.

Let’s continue to look at some of the equipment fitted to Escapade.

Raymarine AIS Class B Transceiver

This is a really useful piece of kit – but beware of over-reliance on what it tells you!

The best feature is that it is linked to the chartplotter. This means that you can see AIS tracks overlaid on the chart; if you turn on the radar as well, you get some very useful information.

The disadvantages of AIS are as follows:

  • The position displayed may not be ‘real time’. Yachts in particular, can be slow to update. This is because they are Class B transmitters – and have to wait for a gap in the transmissions of the Class A vessels (anything over 300 tonnes) before they can push out their data. In a busy waterway, that can mean a significant delay. You can see this if you overlay your radar picture on the AIS data – see how often the AIS icon lags behind the radar echo.  Worse, slow moving contacts update their positions less frequently. Worse still, far too many owners leave their AIS switched on when they leave their boats in the marina for months on end – just so that they can see if anyone has stolen it. All those utterly irrelevant transmitters are queuing for space on YOUR receiver…
  • The vast majority of vessels do not transmit on AIS, so if you think that watchkeeping now consists of setting your system to alarm on for new AIS contacts, please think again!
  • Closest Point of Approach (CPA) data may not be accurate. My advice is to take a visual bearing every time and abide by the Collision regulations – particularly Rule 7 which deals with the risk of collision.

The big advantages are:

  • Other vessels are aware of who you are (assuming you have a transmit capability) and a pretty good idea of where you are.
  • Crossing a shipping lane, it can be very useful to correlate what you can see with information on ship’s name etc – and importantly the likely course and speed of the other vessel.

If you can afford the transmit capability, invest in it.

The International Maritime Organisation (IMO) are engaged in devising the next generation of AIS. Don’t hold your breath, but it should enable vessels to talk to each other automatically (useful in the autonomous vessel world), allow the operator of a Class B system to change their status from ‘under sail’ to under engine’ – and probably inform you whether the ship you are tracking is manned or unmanned. Don’t hold your breath for this though – nothing before 2028.

IPad and Mobile Phone

A staggering number of recreational sailors navigate exclusively on their mobile phones. Fine, except when they rush up to the bow to take a photo of dolphins with their primary navigation device – and drop it in the ‘oggin. Or use it to watch the rugby and wonder why the battery has gone flat. And can you really navigate on a screen the size of your hand? Ask the chap who put the Volvo Ocean racing yacht ‘Team Vesta’ on a reef off Mauritius about the risks of displaying electronic cartography adequately… (a whole subject in  I will return to).

Undoubtedly mobile phones equipped with a very reasonably priced charting App such as Navionics can be an extremely useful ‘aid to navigation’, as a quick reference source in a discussion, or to get the latest weather information (we use a mix of Windfinder Pro, Windy and (in the Solent) Solentmet).  Some yachtsmen sing the praises of ‘Savvy Navvy’ but personally I prefer to select my own sources of data and compare them with more traditional media – such as my hard copy almanac.

We use the Navionics App on a 10 inch IPad for quick route planning and as a backup (we went through a period where the cockpit chart plotter had an uncanny ability to know when we were entering a new port or anchorage and simply shut itself down. The big advantages over the phone are screensize and the fact that you aren’t using it as a personal communications device.  The big disadvantages of both are:

  • They don’t float
  • Battery life can be variable
  • Connectivity (although if you are using it as a chartplotter, all you need is a model with a built-in GPS.

Glomex 5G Mobile phone fixed antenna

The Glomex 5G antenna on Escapade’s stump mast. The small blue cap covers the SIM Card slots.

SATCOM data is expensive. In 2023 we deployed to the west of Ireland and wanted the ability to work from the boat. We could not have afforded to run the iridium and were unwilling to risk being out of mobile phone signal range when we knew we would be working. So we invested in a decent mobile phone antenna. After much research, we purchased the latest Glomex 5G offering. You can insert two SIM cards into it (so don’t mount it up the mast where you cant get at it) and use your mobile phone to control it using the wifi feature. It worked really well. Mind you, the Irish have invested heavily in their mobile phone infrastructure. That said, we have faster Internet connectivity from Escapade alongside in Gosport than we do from our home just a mile away.

Bottom line: a booster aerial for your mobile phone reception is a worthwhile investment, particularly if you can insert a couple of local SIM Cards into it – and be prepared to switch around as you go. Purchasing local SIM Cards is easier than you think – we used the local marina as our ‘address’ and set up direct debits for monthly contracts which we cancelled as we left the area.