“OK, there’s something to this,” I murmured to myself, cornering the RIVA-equipped RXT-X. Having a bone-stock 2018 Sea-Doo RXT-X 300 generously in my possession for most of the year (thanks to Sea-Doo), I had become rather accustomed to how the new ST3 platform liked to behave in most conditions. In earlier reviews, I noted that the hull loves – nay, demands – to be trimmed down and throttled through the hairpins. It’s an aggressive design for sure, and those already familiar with the race-ready RXP-X will have no problem transitioning to the larger ST3. Sure, it took some getting used to initially, but once I became comfortable with the craft’s nuances, it was second nature. That is, until now.
At the time of my review, the production version of RIVA Racing’s new Pro-Series Sponsons for the 2018 RXT-X 300 weren’t quite ready. The final versions wouldn’t be made available to the general public months later, only now, late in the summer. In fact, only Sea-Doo X-Team/RIVA Racing support team rider Erminio Iantosca had raced with them during the first P1 AquaX races earlier in the season. Privately, Erminio told The Watercraft Journal, “The RIVA sponsons help make the T-X more stable on a straight line; [and] makes the ski corner way better and smoother. All around, [they] total[ly] help make the T-X handle better and creates a better feel for the rider.”
The hardest part of the development process was the fact that the new Pro-Series sponsons would not work on any other Sea-Doos using the ST3 hulls, including the GTX 230/300, Wake, or even the RXT 230. Sea-Doo had molded in a completely different bolt pattern for the RXT-X 300 unlike the other machines. This was a one-off, plain and simple. RIVA Racing’s own Dave Bamdas told me, “We went through 8 or 10 different prototype blades before settling on this design.” Precision machined from a high-strength, proprietary composite material, the blades are progressively stepped upwards (completely opposite of RIVA’s Pro-Series sponsons for the Yamaha GP1800), which helps plant the nose and mid-ships tighter to the water surface.
The 5-way adjustable blades feature billet recessed inserts, mounting it to a fixed backing plate, all attached with stainless hardware. Replacing the unusually-shaped one-piece plastic sponson, the RIVA Pro-Series radically changed the attitude of the RXT-X 300 – and all significantly for the better. Straight-line stability is a night-and-day improvement, particularly while tracking through erratic chop (which RIVA’s test lake had quickly become after 20 minutes of hot laps). Certainly snapping muscle-straining hairpins was made easier by the sponsons’ addition, but it was the predictability of the turn that impressed me most. Rather, the knife-like keel of the ST3 slit through the whitecaps like a surgeon’s scalpel. Clean and precise.
“[The] billet aluminum stabilizer wing allows you to tune lean-in handling characteristics,” Bamdas went on, touting the adjustability. While the sponsons’ legality for all IJSBA classes is a boon for racers, I felt strongly that the recreational rider would greatly benefit from a pair (myself included as the race-proven sponsons delivered such a significant improvement to handling and stability while at speed. Priced at $499.95, RIVA’s Pro-Series Sponsons for the 2018 (and up) Sea-Doo RXT-X 300 are an inexpensive way to radically transform the natural attitude and handling of the craft. In fact, I’m seeing about getting a set for my loaner until Sea-Doo pries it out of my hands next year.