Biggus
You say "The fishing vessel in question has GPS these days, as does the rescue helo. Therefore the requirement to "find" the vessel, and to "conn" the helo on have largely disappeared. It is almost a case of "nice to have" rather than essential".
I disagree. The system you describe works well if the crew of the vessel in question speak the same language as the helo crew - English, in this case - and is able to quickly relay that position to the helo. Unfortunately, it sometimes proves extremely difficult to communicate in a common language with our non-fluent EU colleagues and comms can be relayed via several sources/translations before actually ending up with the crew of the helo. therefore, any GPS position passed to the helo crew via a remote (foregin) MRCC, etc, is only as accurate as the last time it was updated. So picture the scene when the rescue helo pitches up, in fog or at night, at extreme range with only 20 minutes fuel on scene and the vessel in question is not there. The crew then waste valuable time swanning round trying to locate said vessel, and even 10 miles between last GPS update and actual position can lead to considerable delays in location. In this case, the ability of another airborne asset to "find and conn" is invaluable and hardly a "nice to have".