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INTRO

If your idea of fun is messing about in boats then don’t forget to take your phone with you, it could even save your life. Rick Maybury investigates marine mobility

 

COPY

Chris and Georgie Brown have good reason to be grateful to their  NEC P3 cellphone and the Vodaphone network. Two years ago, whilst delivering the 40-foot yacht ‘Interloper’ from Hamble to Torquay they discovered to their horror that the rudder had broken away. They were 20 miles from the shore, out of sight of land and in atrocious weather conditions. Immediately they tried to put out a ‘mayday’ message using the boat’s VHF ship-to-shore radio, but the storm had ripped the aerial off the mast, it was useless. Then Chris had an idea. Whipping out his trusty mobile he fought his way to the bow of the boat and dialled the coastguard. ‘It seemed like days’ said Georgie, ‘but I guess it was only around two and a half hours before we were rescued’. The Weymouth lifeboat came to their assistance and took them in tow, back to shore. Had Chris not been able to contact the rescue services there’s every chance the boat would have got into very serious difficulties, possibly with fatal consequences.

 

We tend to think of the cellphone network as a land-based communications medium but that incident clearly illustrates its value to sailors and potential for use in boats, in and around our coastal waters. In fact Cellular phone coverage is actually much better on the water than it is on land. Cellphone sites near the coast are often mounted high up on headlands and cliff-tops. This gives the best coverage inland, but often by accident, rather than design  it also extends some considerable way out to sea. Quite simply the sea is flat, and there’s usually nothing to get in the way of the signals.

 

Vodaphone tell us that it’s actually possible to make calls using some of their UK cell sites, from the Northern coast of France, though it’s not encouraged, and the French authorities are none too happy about it either, so don’t tell anyone... Analogue coverage is markedly better than digital, Vodaphone say some cell coastal cell sites can be accessed up to 80 kilometres out to sea, though 60 kms is a good average. GSM coverage is considerably less, they quote a maximum of 35 kms. Cellnet are a little more cautious, they reckon contact is possible without any trouble within 16 to 20 kms of a cellular base station, though they acknowledge it varies considerably from place to place. The network coverage maps have very few gaps but Cellnet and Vodaphone have recently undertaken a joint venture to improve reception in and around the Highlands and Islands. They’re installing a further 200 cell sites at a cost of £40 million. This will bring some of the busiest, but at the same time, the most remote shipping channels into the network.

 

Cellphones at sea are not only useful for making emergency calls, or keeping in touch, there are a number of additional services available to mobile phone users. They include up to the minute Met Office marine weather reports. Cellnet subscribers can dial-up a service called Marinecall, which divides the UK up into 15 regions, they’re listed in the Cellnet handbook supplied with new phones. This handy little booklet also includes a general Coastguard number, and the access codes for making calls to ships at sea, via the Inmarsat satellite communications network. Be warned that some of these services may not be available on the low-usage tariffs.

 

So what equipment will you need? As far as we’re aware no-one manufactures or markets purpose-designed marine cell phones in the UK. There appears to be very little demand for specialist equipment as ordinary hand-portables, car phones and kits function perfectly well in boats. The only additional considerations are to ensure the equipment is adequately protected from sea water, and the elements. It’s prudent to take some basic security measures  -- to prevent theft and unauthorised use -- and you will probably need a specialised antenna, if the phone is going to be used with an adaptor kit or permanently installed.

 

Ordinary car cellphone aerials are not much use on boats. They depend on the metalwork in a car body to provide a ‘ground-plane’, to work properly. Most boats are made of glass-reinforced plastic (GRP) glassfibre, or wood, which has no ground-plane effect.  As we’ve said this is a relatively small market and we have been able to unearth only a small number of ground-plane independent antennas, we’ll conclude with a brief round-up of a selection of suitable antennas and fittings in a moment.

 

However, there’s no reason why you can’t use a normal hand-portable cell-phone, even without an external antenna the coverage is likely to be more than adequate for use in and around British waters. The first and most obvious consideration is an adequate power supply. That means either taking several spare batteries along with you, or better still, some way of tapping into the boat’s power supply. Most small vessels have 12 or 24 volt DC systems, so power cords and talk and charge adaptors, designed for in-car use, are ideal. Obviously larger craft, with 240 volt AC supplies are no problem either, just use the phone’s desktop charger.  Hooking the cord up to the boat’s electric’s shouldn’t cause too many difficulties, a few boats have cigarette lighter sockets, but it’s a simple enough matter to chop off the plug and wire it in.

 

It’s a good idea to protect the handset against coming into contact with sea water. It’s highly corrosive and if any gets inside the phone it could cause irreparable damage. A normal leather carry case gives a fair degree of protection, but it might be a good idea to slip the phone inside a plastic bag as well, just to be on the safe side. Mobile phones probably don’t float very well -- we haven’t actually tried it -- so maybe attach the phone to a line on your belt, just in case you get careless.

 

Now for those marine antennas and fittings:

 

ALLGON

Allgon have a range of marine fittings, designed to work with their MA416 ground-plane independent antenna. It’s a 620mm  glass-fibre encased whip, fully protected against sea water. The fittings include fixed or ball jointed deck mounts (part no’s 4117.2100 or 417.2200), or a pulpit tube mount (417.2000). Either of the mounts can also be attached to a pulpit bracket (2135.01.00.00). The antenna retails for around £40 and the mounting brackets cost between £15 and £30.

 

Contact: Allgon Antennas, Unit 11, The Courtyard Whitwick Business Park,

Stenson Road, Coalville, Leicester LE67 3JP.

Telephone (01530) 510013

 

PANORAMA

The BS900 is Panorama’s solution to cell-phones at sea. The ground-plane is provided by three flexible helical elements that screw into the base, the radiating element is a 280mm plastic coated whip. The antenna is attached to a mast mounting bracket and comes supplied with a simple to fit U-bolt fixing. Very well made with excellent weather protection. The antenna and fixing kit sell together for around £75

 

Contact: Panorama Antennas Ltd., Frogmore, London SW18 1HF. Telephone 0181-870 7641.

 

WALLEN

Wallen have two marine antennas in their range, they’re the PA017 and PA017S. The main difference is length, the radiating element is the same in both cases, but on the PA017 it is elevated, giving the antenna an overall height of 1.5 metres; the PA017S is just 400mm long. Both antennas are ground-plane independent colinear types, manufactured in fibre-glass. They’re supplied with ratchet-mount bases and come complete with 5 metres of cable. Both types have a typical retail price of around £52.00.

 

Contact: Les Wallen Manufacturing Ltd., Unit 1, Trinity Place,

Ramsgate, Kent CT11 7HJ. Telephone (01843) 582864

 

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Ó R. Maybury 1996 0703

 


 

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