5th page indeed! Thank you for your feedback on this matter, it is very helpful. I think I am going to suggest we trial a propguard, (may even have a go at fabricating one myself), if only to eliminate it. Zapcats are running them apparently with no ill effects, although tey are usually running at speed and jumping, where a glancing blow is the risk rather than slow chugging where it can chomp away at limbs and things.
We will also contact the manufacturers and see if we can get access to a decent sized demo Jet outboard to see how well they work. The jet could be an ideal answer if it has enough poke to cope. If successful, the entire growing RIB fleet could all be equipped with them. Looks as though we are about to order 2 more new 6.5 metres for next season
(pending the budget getting approval).