English channel with (off the shelf, gutted) boat on autopilot.

Hi, I’d been looking at flying a UAV from the Dover to Calais or vice versa and got so far as selecting a Skywalker and researching specs for it, but a previous thread I read suggested this would be a no-no legally without “eyes on” the drone trhoughout. As a result, boat looks to be the way forward.

Plenty of groups and individuals have tried to get a boat one way or the other across the Atlantic, all lost to date, all have been custom built, with quite some outlay in most instances. Dover to Calais seems like a relatively easy goal to kick.

At the narrowest, we’re only looking at 30 or so KMs between France and the UK, assume 50kms needed for optimal landing point and taking into account drift.

Are there any off the shelf RC boats out there which could feasibly make this trip on battery in up to 7 hours at 4 knotts (considering distance, I don’t foresee a need for solar), without being at a a monumental risk of flooding? I’m assuming that the only original item is likely to be to be the body by the time this is finished. Trying to do this on the cheap, so suggestions and input welcome.