Thanks for your comments.
Having been on the boat I can confirm first hand that the sequence of events had or indeed has absolutely nothing to do with the build of the boat, achievements to date are an obvious testament to that.
It appears that the vibration was caused by the starboard drive shaft which developed a very strong vibration approx 1 mile off Old Harry. All drive on starboard was then lost with engine running fine and kept ticking over in neutral to cool down whilst we made for Poole unaided at 5knots. It was only when the overheat alarm sounded on the starboard engine we shut it down and lifted the engine lid to discover it was almost completely full of water.
It appeared that the 3 bilge pumps were overwhelmed despite us also pumpingon the 4th manual pump, whilst it is partly right a RIB is unlikely to sink this ofcourse does not make allowance for the fact that if it is overwhelmed by weight at the stern the risk if that the should the tubes or freeboard be on the waterline, water will simply pour in and cause the boat to sink by the stern, probably with her front 15 foot floating and all the very expensive engines/kit underwater nicely on the Poole/Chebourg ferry path. Given the choice between this and a lifeboat with a salvage pump which would avoid this I think we'd probably all agree a call to the coastguard was a wise move.
At the time we had on board a liferaft, grab bag, epirb and grabner lifejackets all of which kept the situation very calm until assistance arrived.
Salterns were very helpful in allowing us to be lifted out 6pm Friday and the tubes are fine, just deflated to compensate for the enormous pressure lifting a RIB in a hoist can exert on them. Engines were doused in fresh water and run up absolutely fine and all engines electronics appear to be faultlee - fantastic testament to Dave Crawford Marine on that one!
All in all not ideal but she seems to have escaped with very little evidence showing of the experience and will doubtless be out again very soon!