binbrook, I'm sorry that your perfectly reasonable question remains unanswered. I suppose that Sea Survival is as much a preoccupation these days as it was in ours and would hope that the seaworthiness of the Single Seat Dinghy can be relied upon accordingly.
The problem is that these days the airworthiness of the aircraft, and in particular their escape systems, is of even greater concern. It seems that the Hawk's Mk10 ejection system never possessed a Safety Case, an absolute prerequisite for airworthiness, and hence it must be unairworthy. If that is so then the aircraft itself is unairworthy, and yet it still flies. That is a matter of very great concern.
Like you I would expect RAF Flight Safety, in the guise of Wg Cdr Spry, to address these concerns on this very thread, a sticky dedicated presumably to Flight Safety. Instead he is conspicuous by his absence and our concerns go unanswered, though in fairness it is more likely due to direction from on high.
A very different regime these days it would seem compared to that which you and I were lucky enough to inhabit. We need to ask ourselves why that should be.