WOW! A friend of mine has aboat similar to that one with the 3 300's. His boat's name is No Limit. People often ask him why do you have 3 engines on there - the common reply is because I couldn't fit 4. Does about 90MPH in flat water and comsumes more fuel than my yacht per hour.
The 1325HP jet powered boat is a competition class Pratt & Whitney jet engine. Those are usually put on hydrofoil class racing boats... I don't know what this guy is doing with that engine on that boat though. He has to use that in the river because that kind of power with that transum on open water is way too dangerous unless he plans on never driving it past 20MPH.
Never-the-less, gorgeous boats.