Noticed those little blades on the back of your buddy’s ski and aren’t sure what they’re about? The performance handling specialists at Pro Watercraft have you covered.
Rear sponsons have been on jetskis since some of the first models came out, but the technology has evolved for the better. Initially, big, blocky fins were attached to the sides of the bottom deck on early models, with the intention of more stability for the rider. While the concept was right, the design wasn’t quite there.
Flash forward to now — companies have been tinkering and testing rear sponsons for years.
The original concept has evolved a little. Rear sponsons are an easy bolt-on modification that’s usually added to the bond rail in the rear of the watercraft. Chris Hagest at Pro Watercraft jumped into testing out rear sponsons early in the game — his goal was to not only add stability but to also chase rear grip.
At Pro Watercraft, we have several different rear sponson options that were designed with different functions in mind. Here’s the break down:
OBF Rear Sponsons
Our over-bond-flange (OBF) sponsons are our all-around, entry level rear sponson. These bolt *over the bond flange* for easy installation, and instantly add more stability to the ski. By effectively widening the footprint of your stand up, you get more stability in a straight line. This helps alleviate uncomfortable side-to-side hopping or tipping, while still giving you the ability to smoothly roll over into a turn.
Our OBF sponsons are recommended for 440/550s, 650s, squarenose Super Jets, and Kawasaki X2s.
XL Performance Rear Sponsons
Go big or go home, right? Our XL performance rears are really popular among racers or intermediate to expert level rippers. These sponsons also bolt on to the bond flange for easy installation. Their primary focus is rear grip, giving faster riders more confidence that their ski won’t spin out. The XL performance rear sponson is tighter to the hull than our OBF sponsons, giving riders the ability to really lean hard when carving tight turns.
The XL rear sponson is intended for 440/550s, and 650s. It’s used by a lot of racers and intermediate to expert level rippers.
Wedge Rear Sponsons
Our wedge sponsons are a unique design, and one of the only ones in the industry. There is a balance between grip and speed, where sometimes more grip can slow you down a little. For the people looking for a little more top end, while still keeping some benefits of rear grip — we came up with the wedge sponson. This sponson effectively fills the back corner of your bond rail area, creating lift as your ski travels across the water. This eliminates a lot of rear end drag, and helps you pick up some top end, while also making it easier to break the back end loose if you want to make a sharp turn.
Our wedge sponsons are recommended for SXR 800s/1100s, and most Yamaha Super Jets.
Performance Rear Sponsons
Our performance rear sponson was one of our first great designs for rear sponsons. These sponsons are used by recreational riders and racers alike. Their primary focus lies in the turn, giving you a smooth roll and lots of rear grip. These are used by a lot of SXR 800/1100 and SuperJet riders.
Performance Mid Sponsons
Mid sponsons?? What are those you ask?
Our mid sponson takes the effective design of our performance rear sponson and moves it more to the center of the ski. This effectively moves your pivot point, making the ski turn more around the center than the front/rear. This gives you a lot more control over the ski and helps with hook up as well.
We recommend these for SXR 800/1100s, SuperJets, Kawasaki 650s and they work especially well with the Kawasaki 750.
Double-Blade Rear Sponsons
These sponsons are for the SXR 1500 only. These combine the concept of rear and mid sponsons together, giving you a double-blade sponson perfect for carving tight and fast turns. If you’re in need of something for rough or all-around conditions for your SXR 1500, check out our performance rear sponsons for the SXR 1500.
Not sure which rear sponsons are right for you?
Picking out a set of sponsons depends on your riding style and your goals. Depending on what kind of riding you are doing, different sponsons may work better. The best way to see what works best for you is always to give it a try, but hopefully this breakdown helps clear things up for you.
REAR SPONSON BUYING GUIDE
REAR GRIP + BIG STABILITY
Great for friends or family riding your ski, lots of stability and great rear grip.
BIG REAR GRIP + STABILITY + SMOOTH ROLL
Great for racers or intermediate to expert level shredders. Elevated rear grip, better side to side stability and smoother roll into turns.
SPEED + GRIP
Great for racers or riders looking for a little more top end speed, and like breaking the back end loose for some tight turns.
CONTROL + STABILITY
Great for skis like the Kawasaki 750 that have a tendency to hop a lot, or racers who are looking for more control in the turns.
BIG REAR GRIP
Great for riders and racers focused on strong rear grip.
It’s a lot to take in… but rear sponsons can really elevate your ride. If you have any other questions, or if you’d like some advice on which rear sponsons will work best for your ride, don’t hesitate to call or email the handling experts at Pro Watercraft.
