If anyone is interested in purchasing and re-furbishing an ex MOD Rib, there are some that have just been released for sale. They are Arctic 28's and Arctic 22's, and although probably not in the best of condition, they are built to extremely high specification by Halmatic. The A28's are more than likely ones that have been in service with the Special Boat Squadron.
They are being sold by Babcock Disposals and the web site is
http://www.babcockdisposals.co.uk
