On the basis that passenger hovercraft in the UK are registered with the CAA and the SRN4 were powered by aero engines, I'm taking a punt and flagging this up here.
A terrible shame (again) if one of these leviathans are not saved for posterity. The Saunders Roe Princess class flying boat was lost and it would seem absurd to lose these too.
Petition to save last cross-Channel hovercraft - BBC News