Croc,
I did it on a 43ft Perry Cat.
Take a stinger suit and wear it. (depending when your going)
Can you rig on endless loop to keep the boat in deep water and yet be able to haul it to shore when ever required.
We got the feeling the shops on Hammo would take any money any chance they got. The water you may get on Hammo was such that one of the girls with us got dehydrated from just drinking booze as she hated the taste of the water so much!
Cheers
Chimo