I work on rigs all over the north sea and a product like this would be very useful as I can be trying to locate positions on the deck 3 or 4 levels below. Would the device pick up a signal out at sea surrounded by metal?
It would probably work so long as you were close to the edge of the platform. But DO NOT take one offshore unless you are going to use it in a 'safe area'! Operational Oil and Gas Platforms mostly consist of areas classified as Hazardous and any electrical equipment used within those areas need to be rated accordingly. This device has not been designed for use in such areas. Just Google ATEX for more information.