Communications at sea


We have come a long way from smoke signalling to high speed internet access along an ever steeper curve of technical development. It is interesting to note that the latest technologies have not totally superseded the old and trusted ones. Smoke signals should be on board every life raft together with an Epirb and VHF radio. Old and new technology together.

Radio signals.

VHF is as much in use now as the mobile phone for on shore communications and ship to ship and ship to shore communications. The cruisers nets could not exist without VHF.

HF radio communication is still a staple for most long distance sailors. It provides not only the radio amateurs also known as Ham operators but everyone with a HF radio with a cost effective way of talking to fellow sailors, communicating with S&R centers, even sending and receiving emails to and from HF equipped land based radio stations.
Cost plays an important role.
The basic requirement is installing a SSB radio connected to an antenna via an antenna-tuner and earthed with an earth plate or shoe under water.
Installation is best left to experts in this field and gives the sailor voice capability.
By adding a Pactor modem one can connect a laptop to the HF radio and it becomes possible to send and receive personal emails or request weather information such as Grib files by email. The connection with the land based stations is not always easy and trouble free caused by propagation problems with radio waves over long distances.

The cost is in the purchase and in the installation. Use of the radio for voice is cost free and use for email requires a small amount per year to providers such as Sailmail for non Hams or Winlink for Ham operators.

chart tableThe Uniden Polaris VHF radio and the popular Icom SSB transceiver linked to the laptop via a Pactor modem for emails and weather forecasts.



Internet technology has given the long distance cruiser a myriad of ways to stay connected.
WAP or hotspots in marinas give wireless access to the internet from the comfort of one’s own yacht effectively superseding internet cafes.
To make this work one connects a laptop, wifi enabled or with a wifi adaptor, wirelessly to this hotspot. Sometimes these hotspots are free sometimes one needs to pay for data. This works fine and is cost efficient when on land or close to land and within range of a usable wifi signal in the marina and when the signal is not shielded by a huge motor launch. With a high sensitivity wifi antenna one can connect sometimes up to 100’s of meters from the Wifi antenna. The cost for data depends on who owns the hotspot. Some cafés and restaurants offer it for free to clients some providers make a living out of it and charge for data over a period of time. To give more crew members access one can install on board a wireless router with a high sensitivity antenna. Be careful, this sort of connections can easily be compromised so do not do your banking via this system.

A warning. Sensitive information exchange such as banking should never be done via a wifi hotspot. One is never certain how well and how far the dat exchange is encrypted and who can listen in. Sometimes a WAP is a rogue designed to trick you and snoop on your data.

Your own mobile WAP or Hotspot.

A smart phone or tablet computer with 3 or 4G capability can connect to the internet using a Sim card with (pre)paid data or a contract with data via the cellular network of a provider. Sometimes up to 10 miles offshore.
This is useful when moving from place to place within one country. within reach of a mobile phone signal. Cost can be high when one roams abroad. The cost effective solution is to buy a Sim card from a local provider with a good coverage in the visited country. In a never ending technological progress one can now create one’s own hotspot to connect more devices on board using one’s own smartphone through a process called tethering.

Better still one can buy a dedicated wireless router to be connected through a sim to any cellular network to be used as the hotspot on board. Many of these wireless devices are on the market such as NetComm Myzone, Dlink/Mypocket, Alcatel One Touch and Mifi and many more are available. Some are linked to one provider some accept sims from any provider.

A satellite connection is necessary when further out at sea.
Only the providers such as Inmarsat and Iridium currently offer global coverage although Inmarsat doesn’t cover the poles.
Inmarsat en Iridium have their own choices of hardware and various services and contracts that go with the hardware; for voice only, for voice and email and for internet access. On top of the cost of the purchase of the hardware comes the cost of installation. An 11 kg antenna mounted at 2 m above deck requires a substantial SS pole and probably strengthening of the mounting position on the yacht.
The cost of voice minutes and data is not negligible but the connection is mostly immediate, trouble free and clear. For example when sending a few emails one sends the Grib file request first and receives the answer mostly directly after sending the last email out.

Make sure to disable updates for software including your anti virus program and disable  your wireless yacht network since that will gobble up time and money. Do your updates when on wifi in a marina.

The 11 kg antenna of the Iridium Pilot needs to be fitted on a heavy duty pole having a clear view of the sky
The 11 kg antenna of the Iridium Pilot needs to be fitted on a heavy duty pole with a clear view of the sky

It is necessary to be clear about ones objectives when choosing which system to purchase. A supplier who speaks your language in terms of understanding your needs can save a lot of money.

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