Ah yes indeed we spoke about this before. Shame to see them going and it does conjour up a lot of nasty possibilities not having them in situ. Good link that Howard.
Our own knowledgable man of the seven seas, young Ed C himself...has put some very good stuff about these vessels on the thread below. Trouble on the Rough Seas. There are hazy pictures of one coming into action to assist the Seafrance ship..more here
http://www.doverforum.com/letters/viewtopic.php?id=8051