Fourth Element Proteus II Review: The Wetsuit That Earns Its Price

I bought the Proteus II because I was tired of being the diver who got cold first. Most weekends I'm in the water off Jupiter or out of Riviera Beach, usually three dives on a boat day, and the suit I had before would let me down somewhere on the second tank. It dried slow, it flushed cold every time I rolled, and by the third dive I was just counting minutes. So I spent the money on Fourth Element's flagship and dove it hard for a season. This is what I found.

What it is

The Proteus II is Fourth Element's top-tier neoprene wetsuit. It's the suit they put their best material and construction into, and it's positioned above their entry and mid-range options. The headline feature is the lining: a plush thermal liner (their Hydro-T fabric, made partly from recycled material) that sits against your skin and traps a warm layer of water fast. It comes in the usual thickness options — 3mm, 5mm, and 7mm — and in a full men's and women's size range, so most people can find an off-the-rack fit that's close.

It's a full one-piece suit with a back zip on the standard cut. The neoprene is quality stuff with good stretch, and the seams are blind-stitched and glued, which is what you want for warmth and durability. None of that is exotic on paper. What makes the Proteus II worth talking about is how all of it comes together in the water over a long day.

What it does well

Warmth is the obvious one, and it delivers. The thermal lining is the real story here. That fuzzy interior does two things: it holds a warm water layer against your body, and because it's hydrophobic, it doesn't stay soaked between dives the way a plain nylon-lined suit does. On a boat day that matters more than people realize. You climb out, you're sitting in the wind during the surface interval, and a suit that sheds water keeps you warmer for the next drop. I noticed it most on the third dive — the one where I used to get chilled even in summer. With the Proteus II I was still comfortable when I used to be done.

The warmth-to-flexibility balance is genuinely good. A lot of warm suits feel like armor. This one moves. I can reach my valves, work a reel, and get into the suit without a wrestling match — though like any good neoprene, it's a fight to get on when you're dry and effortless once you're wet. For boat diving where you're doffing and donning multiple times, that flex earns its keep.

Build quality is the other thing I'll vouch for. After a full season of salt water, sand, sun, and being stuffed in a gear bag, the seams are intact and the lining hasn't pilled or torn. The neoprene hasn't gone soft or compressed noticeably. This is a suit built to last several seasons of regular diving, and that longevity is a big part of why the price makes sense.

• Thermal lining: warm, fast to trap heat, sheds water between dives.
• Fit and flex: warm without feeling stiff; good for repeated entries.
• Durability: seams and neoprene held up to hard weekend use.
• Recycled content: the liner uses recycled fabric, which I'll take if it performs — and it does.

Where it falls short

The price is the first honest tradeoff. The Proteus II costs real money, well above budget suits from the big-box brands. If you dive a handful of times a year in warm water, you do not need this suit and you won't get your money's worth out of it. The value is in the durability and the comfort over many dive days. Occasional divers should look down the range.

Fit is the second, and it's the one that can make or break the suit for you. The Proteus II fits a fairly standard body shape very well. If you're long in the torso, short in the leg, or just built oddly, an off-the-rack suit — any off-the-rack suit — may not seal the way it should, and a wetsuit that doesn't fit snug doesn't keep you warm no matter how good the neoprene is. Fourth Element offers a wide size range, which helps, but if the rack sizes don't land on you, you're either looking at a different brand's cut or a made-to-measure suit. Try it on, and if you can't, buy from somewhere with a sane return policy.

And the last point is just physics: a wetsuit is still a wetsuit. The Proteus II is excellent, but it floods and flushes like any wetsuit does. On a cold winter day with repetitive dives, you will still feel the water move when you roll, and you will eventually get cold if you stay down long enough. No neoprene suit fixes that. If your diving lives in genuinely cold water or long deco hangs, this suit has a ceiling, and that ceiling is the same one every wetsuit shares.

What thickness for Florida

This is the question I get asked most, so here's my straight answer for South Florida diving.

5mm — the year-round do-it-all

If you're buying one suit to cover the whole year here, get the 5mm. Our summer water runs into the mid-80s and a 5mm can feel like a lot on a single shallow dive — but the moment you're doing three dives, or dropping onto a deeper wreck where you hit a thermocline, or diving anytime from late fall through spring when the water sits in the upper 60s to low 70s, you'll want it. The 5mm Proteus II with that thermal lining is the sweet spot. It's the suit I reach for nine months out of twelve, and I'm rarely over- or under-dressed.

3mm — summer only

A 3mm is great for July and August single-tank dives, snorkeling, and warm shallow stuff where you'd rather have freedom than insulation. But it's a seasonal suit here. Come November it won't carry you through a three-dive day without you getting cold, especially on the back end. Buy the 3mm only if you already own something warmer or you genuinely only dive in the hottest months.

7mm or a drysuit — winter and the cold-sensitive

If you run cold, if you do long bottom times, or if you're hanging on deco where you're stationary and not generating heat, step up to the 7mm — or honestly, consider a drysuit. Plenty of the deeper-wreck and tech crowd around here go dry in winter for exactly that reason. A 7mm Proteus II will keep most people warm through a winter boat day, but once you're doing extended hangs in cooler water repeatedly, the wetsuit ceiling I mentioned starts to bite, and dry is the real answer.

Who should buy this

Buy the Proteus II if you dive regularly and you're tired of compromising on warmth. If you're out most weekends, doing multi-dive boat days, and you've felt that third-dive chill, this suit is a real upgrade and the price pays for itself in seasons of comfortable, durable use. The thermal lining is the difference-maker, and the build quality means you're not replacing it in two years.

Don't buy it if you dive a few times a year, if your budget is tight and you only need warm-water coverage, or if your body shape doesn't match an off-the-rack cut and you can't try one on first. And don't buy any wetsuit expecting it to do a drysuit's job in cold, repetitive, stationary diving — that's not the suit's fault, it's just what neoprene is.

The verdict: the Fourth Element Proteus II is the best all-around wetsuit I've owned, and for a working South Florida diver the 5mm is the right call. It's expensive, the fit demands attention, and it can't beat the laws of physics on a cold winter hang. But for warm, comfortable, durable year-round diving here, it earns its price. I'd buy it again.