I just bought a Yamaha SX-230 last month and love it. It does about 50-51 with half a tank and two people. It is a comfortable boat that is quick off the line. It is kind of tricky docking with the twin jet. The throttle is a little tight and touchy. I hope that it breaks in with time. I launched it in Laughlin NV and drove it all the way down to lake Havasu, and it did great thru the shallow waters (2 feet according to the on board stock depth gauge). It also did great thru some rough 3-4 foot wind waves across Havasu lake. The stereo sounds really good, and has a really cool remote control on the rear of the boat. The bimini top is really easy to put up and down and also to cover. I had to pay $480 bucks for a trailerable cover, but it was definitely worth it. I would suggest buying the stock Yamaha cover not only because it is real easy to use, but also it keeps the items inside the boat from flying out. Something that I almost learned the hard way the night that I bout the boat. One of the seat cushions almost blew out. I shouldn't drive 80 mph with the boat I guess. That is another nice thing about this boat, The tandem axle color matching trailer. NO SPARE TIRE though. NO FIRE EXTINGUISHER on board the boat either. Well, I hope this helped. Happy Boating
Chris in SoCal
Yamaha SX230 
