If he spins that motor 6000rpm and has 100% effiency.. it would be about 87mph. So the numbers are off.. I say it is the speed number that is bogus..
Friend of mine had an h2x, went 109mph at Lake of the Ozarks, several years ago. Set a record, not sure if it still stands. At that time he had 1170hp.

I had my 2001 H2X 6.2 (320 hp) running 58mph GPS 21 p/prop @5100rpm, after I instaled the procharger 7lb boost went to 77.5 mph GPS @5150rpm 26 p/prop, engine last for almost 10 hours. Now running 60mph GPS don't remember the rpm on a 377 blue scorpion.

Upper 60's with a 23p prop. 85 mph is impossible with that setup

My buddy has a 05 h2x with the 496 mag and a 26 bravo and the best he runs is 68.

65mph boat

I do believe that boat, and many others are all capable of 85 mph....off a cliff!

72??? No way, never. 67-68 tops for a REAL number without the sun in you back and the wind in your azz BS. I don't think 70 will be possible with the 502 either.

So the real answer to the question "Will a Baja H2X really go 85 MPH if dropped out of a plane" is yes. This is why speed changes you - I guess.

Did you own one? Mine with a 454mag ran 70 1 or 2 times on GPS perfect conditions and ran 67-68 no problem with 2 people. I put 140 hours on the boat in 2 years so I know it very well. Maybe I had a good one, extra straight hull, high x dimension, whatever those are the real world numbers in fresh water. 502 is 30 more horse so I would have to say yes....70 is very possible. 85? not even remotely possible even on the speedo......

Funny, I was having a friendly arguement last night with a guy.
08 h2x 496 non ho. Swears 72 , told him 62-64. Told him the fountain would win. Bench racing and beer what fun!