Modern marine electronic equipment fitted to a craft, regardless of size, is designed to operate normally when in close proximity to other items of marine electronic equipment. Specifically, marine equipment is designed to be immune as far as is practicable to interference from other on-board marine equipment, and to emit minimal levels of unwanted interference, which could affect other onboard equipment. Strict rules have to be met before electronic equipment is approved for marine use.

A mobile phone is basically a land-based device and is not designed to operate in the marine electronic environment. It is required to meet much less stringent rules as regards immunity and unwanted interference. Although it will work onboard most craft, subject to being within range of a base station on land, its use may well cause disruption to the normal functioning of the marine electronic equipment in its vicinity, which could result in danger to persons on board or even on other craft.

Also if placed too close to a magnetic steering compass a mobile phone will deflect the compass under certain conditions and, therefore must not be used or stored within 1m of any compass and certainly not in the helmsman’s pocket.

Users of mobile phones should therefore be aware that disruption to normal operation of marine electronic equipment is a possibility unless the PHONE IS SWITCHED OFF.

Even when not actually making a call, the mobile phone is still active in standby mode and will transmit from time to time to check that it is still in contact with a base station.

Our advice to users of mobile phones on board craft is to refrain from their use when electronic navigation equipment is operational. Users should remember to SWITCH OFF their mobile phones when this navigational equipment is deployed.