The best wetsuit for freediving in Northern California
In our waters the most important thing to look for in a wetsuit is its warmth. If you are not warm enough, you will start to shiver, making it much harder to hold your breath. The warmest wetsuits for their buoyancy are open-cell wetsuits. I recommend buying an open-cell wetsuit in 7mm thickness.
Why is buoyancy bad? To make neoprene, raw rubber is mixed with a “chemical blowing agent” which, under heat and pressure, releases nitrogen gas into the rubber, creating the gas “cells” that provide insulation. On the surface, these gas cells make us buoyant, meaning we have to wear a lot of weight to be able to dive down through the first couple of meters without generating uncomfortable leves of carbon dioxide. But once we start to descend, Boyle’s law causes these cells shrink, displacing less water and therefore exerting less buoyancy. So we get heavier and heavier, making the descent easier but the swim back up harder. For deeper freedives, the difficulty of this return swim starts to become a constraint. So freedivers look for wetsuits which will give them the least buoyancy for the warmth they need.
Why is open-cell good? Open cell wetsuits provide the most warmth for a given amount of buoyancy. “Open cell” means the neoprene on the inside of the suit has not been heat-sealed or covered with fabric, so it acts like thousands of tiny suction cups, sticking to your skin and keeping you extra warm. It also makes it harder to get into, so you will need to spray the inside of the suit with lube (such as a 50:50 mix of hair conditioner and water) before getting into it. But once you are in, it will stick to you like a second skin.
Why 7mm? Some people will say a 5mm suit keeps them warm enough. But to be comfortably warm even in our winter season (December to June), when temperatures can get down to 51F, a 7mm is best. Also, a wetsuit stretches out a bit over time, losing some of its warmth, so getting a 7mm ensures it will still do its job for many years. If you know beyond a doubt that you are a very warm person in the water (perhaps because you have built up brown fat by swimming in the Bay), 5mm is ok.
Why not a scuba wetsuit? You might have noticed scuba wetsuits typically have a zipper in the back rather than being split into top and bottom pieces. This is because they are not open cell, so it is fine to get into them this way. Scuba divers don’t mind giving up the extra warmth provided by open cell, an integrated hood, and the lack of a back zipper, because they aren’t as concerned with minimizing the buoyancy of their suit. They don’t have to deal with the same carbon dioxide buildup as freedivers do when fighting their buoyancy during descent.
The most important feature of a wetsuit in Northern California is that it is warm enough. Your wetsuit should be at least 7mm thick, and have a hood. Surf wetsuits are not warm enough. Avoid buying a second-hand wetsuit that has been stretched out, as it will have lost most of its warmth.
Open cell neoprene will stick to you like a second skin, keeping you extra warm.
If you are getting a two-piece wetsuit (rather than a 1-piece, zip-up, scuba style wetsuit), I recommend getting a double clasp rather than single clasp to fasten your top. A single clasp is too hard to fasten and unfasten with cold fingers.
Not "Farmer John" style
Even though you might think a "Farmer John" style bottom is warmer, it does not end up making much difference if your wetsuit is thick enough. Its disadvantages are that it can make it harder for you to take a full breath, and you have to take off your top to be able to pee.
Best budget pick: Fins and Foam wetsuit
Order from the Fins and Foam store
I chose this wetsuit for our store because it is an open-cell, two-piece 7mm wetsuit with nice additional detailing: a double frog clasp for fastening the top which is easier to operate with cold hands than a single clasp; pads on the chest and knees; and seals on the wrists and ankles.
What this wetsuit compromises on, to get to its affordable price point, is its neoprene. While it uses limestone-based neoprene, rather than the cheapest neoprenes that are petroleum-based, it is stiffer and not as supple as the highest quality limestone-based neoprenes such as Yamamoto 45.
For an entry-level wetsuit while you are still figuring out how much you love freediving, I think this is a good choice.
Currently this wetsuit is only available in Men's cut.
Best upgrade pick: Mako wetsuit
Order from Mako
I like this wetsuit because it is an open-cell, two-piece 7mm wetsuit with the same nice detailing as the Fins & Foam wetsuit (double clasp, chest and knee pads, wrist and ankle seals), but also made of top quality Yamamoto 45 neoprene. This makes it easier to put on; easier to use your arms in; and easy to take a deep breath in. It also makes sizing more forgiving, since it can stretch more around your body.
This wetsuit is available in both men's and women's cuts.
300 - 500
Order from Polo Sub
Custom wetsuits are more expensive, so if you can find an off-the-rack one whose measurements are a good fit for your body, there is no need to go custom.
But if standard sizes are less of a good fit for your body type, or you want to get every last bit of warmth out of your suit, the extra investment might be worth it.
Polo Sub and Elios are two Italian custom wetsuit makers with an excellent track record and options in the $300-500 range - less than many off-the-rack brands. Note that Elios offers Yamamoto neoprene while Polo Sub does not. BestDive is a Chinese wetsuit maker with custom options in roughly the same price range, while Merman (Korean) and Molchanovs (Russian) cost significantly more.
Finally... some brands which stock wetsuits with good women's cuts include BestDive, PoloSub, Mako, Epsealon, Marea, Mares, Beuchat, Waihana, Yazbeck, and Omer.