Re: PWC Speeds
I can give you some info on Yamaha models:
Yamaha's VX is their entry level ski, and it is 3 person. You can tow with it, but it is a little unstable due to the hull design while towing, so OK for small kid towing, but I wouldn't recommend it for towing more than 1 adult. You can ride 2 adults on it plus a small kid, but I would not recommend putting 3 adults on one. The ride is a little bouncy, but not bad, and you do get wet in the chop. Top speed is around 54 mph, and this ski has the best fuel economy of any ski on the market on regular fuel (one reason all the rental places use it). It is also the most reliable ski on the market....just about bullet proof (the second reason all the rental places use it).
Yamaha's FX HO models are nice large 3 seaters that will tow a tube with no problems. I've easily towed 2 adults on mine with a large (Big Mable) tube. The pre-2009 model FX HOs have a 1100 cc engine (160 HP) and will do right at 60 mph (mine does 61 on the gps). They are also very easy on the fuel compared to other skis and you run regular 87 octane, versus premium fuel required in some of the SeaDoo and Honda models. The 1100 cc engine is also extremely reliable, and I would say the pre-2009 FX HO is probably the best choice for a used family ski out there. The ride is very stable (you have to work to turn one over). This ski will plow through rough water, but keep you dry. The newer FX HOs have an 1800 cc engine and will do around 64 mph, but are slightly worse on fuel, even though all Yamaha's run on 87 octane.
Yamaha just came out with a new model ski this year (VXR and VXS) which has the same new 1800 cc engine and will do around 68 mph stock on a normally aspirated engine. This is more of a sport type ski with a less stable hull design (similar to the VX hull) than the FX models, so I would not recommend it for a family ski.
Yamaha also has the FXR/FXS and SHO models that carry the same 1800 cc engine with the addition of a supercharger. The FXR/FXS is primarily a sport/racing model, and the SHO is a high speed cruiser. They will also run around 66-68 mph, but are both real gas hogs, so I would not recommend either model, just because of the fuel consumption.
Hope this helps!