No way that boat would run 300 mph, no matter how much hp it had.
I’ve been on several high speed boats & the fastest that I went on one of them went was 110 mph. It was a $250,000 33’ Daytona Eliminator with twin 525 hp 502s w/EFI. It was a Catamrine designed for high speed. I have seen some 150 mph boats & they looked nothing like that glorified fishing boat.
100mph in a car is not all that fast, but 100 mph on water is FAST!
I’m not sying 300 mph is unobtainable, just not on a raft.