I own a Seadoo 1996 Speedster jet boat. Basically, it's an overblown jet ski. It seats only four, is only 15' in length, but is powered by two 85HP Rotax jet ski engines. Tops out at around 50MPH, and will turn on a dime. The beauty of jet boats is you have no exposed propeller in the back, The 'impeller' is inside a pump housing. Don't have to worry about accidentally running over something in the lake, and I can run in as little as 1 foot of water. Seadoo and Yamaha make the most popular jet boats, and they range in size from 16' up to a 8-seater 24' 240HP.
If you're looking for boats, expect another money pit. There's always maintenance costs for annual upkeep, you have to have a place to store it, a vehicle that can tow it, and the pocketbook to fill it up with the water toys you want to play with. Also not very fuel efficient. Expect maybe 6 gallons/hour on a boat 18' or larger. You can easily burn a 30 gallon tank of gas in one day. In California, I believe they have banned operation of all 2-stroke boat engines on their waterways. So that rules out pretty much any boat built in the 90's or earlier. 4-strokes are more efficient, and you don't have to deal with mixing the oil with the gas.