May 01, 2026

What Makes a Seventhwave Wetsuit Different

Not all wetsuits are created equal. The material, construction, and fit all make a significant difference in how warm you stay, how long your suit lasts, and how it feels in the water. Here's what goes into ours.

The neoprene

We use Yamamoto limestone neoprene exclusively — and have since 1987. Most wetsuits are made from lower-grade, less pure limestone or directly from petroleum. Ours aren't.

Yamamoto neoprene starts life as limestone mined from Mt. Kurohime in Japan, one of the purest limestone deposits on earth. Because it's limestone-based rather than oil-based, it has a fundamentally different cell structure — and that difference shows up in the water.

The closed cell content sits above 93%, some 22–33% higher than competitor materials. Each of those cells is sealed and filled with nitrogen gas, which means the rubber doesn't absorb anywhere near as much water. Your suit stays light, dries fast, and performs the same at the end of a three-hour session as it did at the start.

That cell structure also gives Yamamoto its stretch and durability. You can take it to maximum elongation over 2,000 times without it bagging out — conventional neoprene loses its shape at around 300. The rubber has a cell memory that moulds to your body over time without getting loose.

Our 3mm Yamamoto neoprene is as warm as a standard 4mm. That's not a marketing claim — it's a direct result of the nitrogen cell density.

Not all Yamamoto is the same. We work across multiple grades — #38, #39, and shortly #40 — each selected for specific models and applications. You can read about exactly which grade goes where and why on our About page.

Titanium lining

Our winter suits and Hot Tops use Yamamoto's Titanium Alloy Alpha lining — an ultra-thin titanium alloy film that reflects your body heat back toward your skin while blocking cold from the outside. Yamamoto's own testing indicates it increases thermal performance by up to 40% compared to untreated neoprene of the same thickness. In our Max and Enduro ranges, the Titanium is coated directly onto the rubber before the nylon lining is applied — permanently locking it into the construction of the suit, not a coating that wears off.

Construction:

How a wetsuit is sewn matters as much as what it's made from.

Flatlock seams are used in our summer suits — panels lapped together and stitched flat, creating a comfortable, breathable seam with no raised edges. Ideal for water temperatures from around 15-16-°C upwards, and the construction you'll find throughout our Viper, Siren, and summer Max range.

Glued, blindstitched and taped construction is used in all our winter models. Panels are glued, butted together, then blindstitched on the outer layer using a curved needle that doesn't penetrate through to the other side of the neoprene — creating a watertight seal that keeps cold water out. What most people don't see: every one of our 28 seam points is finished by hand — thread end taken back through the seam, knotted, and sealed with gel. It takes more time, but it's the difference between a seam that holds season after season and one that starts to fail after a few months.

Heat-sealed Melco tape is applied to all inside seams on our glued suits, reinforcing every join for additional strength, comfort against the skin, and an extra layer of waterproofing.

Zig-zag stitching is used to finish cuffs, collars, and zips. Unlike a straight stitch, it stretches with the neoprene — making it far more durable in high-movement areas.

Smoothie panels

Most wetsuits use smoothie — single-sided nylon neoprene — in the chest and back panels to reduce wind chill. Because Yamamoto limestone neoprene doesn't absorb water nearly as much, we don't need to. Our chest panels are full nylon/nylon construction — stronger neoprene panels, longer life.

The fit

Every Seventhwave wetsuit is handcrafted in Christchurch to a size range developed and refined over nearly four decades of making suits for real people in real conditions. Our standard sizes are cut to fit well — not as a compromise, but as a considered starting point that works for most bodies.

For those who fall outside standard sizing or want the closest possible fit, our Custom-Fit option is available across our premium range. Made to your exact measurements, it's the difference between a good wetsuit and one that feels like it was made for you — because it was.

Since 1987, we’ve never found anything that outperforms properly fitted Yamamoto neoprene. That’s exactly why we still do it this way today.