The advantage of a zodiac is it meets all construction and already has a persons number associated with it. Zodiac's have the ability to take alot of passengers. As for safy equipment(extinguishers, flares) that is the same for all boats in that class. As for the size if the vessel, if it is under 5 gross tons and you do not carry more then 12 passengers you have to meet safty regs. and do not need papers. This may change in the future. A zodiac with a 12 passenger rating meets all specs. before it is put in the water. The cost of this would be huge.
The problem with this whole charter thing is it is mostly made of of weekend warriors who think they can make a buck with a boat on the cheap. NOOOOP. Also TC have not figured out what exactly to do with vessels under 15 gross tons, they will.
If I had the money 30ft hurricane class zodiac with 4 stokes on the back. Metro marine unit paid $400,000 + for theirs.
Be Safe
Chet