And remember you have absolutely no control during startup .... you shove the helicopter away from the boat and now you are drifting with the current or wind or whatever .... then you engage the rotor and torque begins to spin the fuselage ... it takes a while until you have enough rpm for cyclic and tail rotor to start working .... even if everything is going bad and you shut the engine off your blades are still turning and will hit trees , boats , or shore .... same as landing .... you have to shut down a safe distance until everything stops turning and then what ???? stand on a float and paddle toward the boat ??
Not much fun .... it would remove the word "leisure" from "leisure boat with a helicopter" .... best wishes and good luck