What Closed Cell Wetsuits Are and Why They Matter for Spearfishing

A closed cell wetsuit is made from neoprene that has been compressed and sealed so that the foam contains no air pockets. This construction makes the suit denser and less buoyant than standard wetsuits, which is why spearfishers prefer them: they reduce the weight you need to carry in lead and make it easier to stay at depth without fighting buoyancy on the way down.

The trade-off is real. Closed cell suits are less stretchy, heavier to move in on land, and they absorb water differently than open cell neoprene. They also cost more. But if you spend significant time below the surface hunting fish, the reduction in lead weight and the stability at depth often outweigh those drawbacks.

The material itself is the same neoprene used in standard wetsuits, but the manufacturing process — compressing the foam under pressure — changes how it behaves in water. That compression is what makes closed cell neoprene so valuable for spearfishing specifically.

Key Takeaways

  • Closed cell wetsuits have compressed neoprene with no air pockets, making them denser and less buoyant than standard wetsuits.
  • Spearfishers use closed cell suits to reduce the amount of lead weight needed and to maintain depth control without constant finning effort.
  • Closed cell neoprene is less flexible, heavier to wear on land, and costs more than open cell alternatives.
  • The suit absorbs water into the material itself rather than trapping air, so it provides warmth through a thin layer of water against your skin.

How Closed Cell Neoprene Handles Buoyancy Differently

Open cell wetsuits trap air inside the foam, which gives them natural buoyancy. That buoyancy changes as you descend — the air compresses, and the suit becomes less buoyant the deeper you go. For spearfishing, this creates a problem: you need more lead weight to stay down, and that extra weight pulls you down faster on the descent than you may want.

Closed cell neoprene has no air pockets to compress. The material itself is denser, so it is naturally less buoyant from the surface down. This means you can use less lead weight overall and still maintain neutral buoyancy at your target depth. The suit's buoyancy stays more consistent as you descend, which gives you better control and less strain on your legs and back from carrying excess weight.

For hunters working at 30 to 60 feet, this difference is noticeable. You spend less energy fighting buoyancy and more energy on the hunt itself. On longer dives, that matters.

Warmth and Water Absorption in Closed Cell Suits

Closed cell wetsuits do not trap air for insulation the way open cell suits do. Instead, they rely on a thin layer of water between your skin and the neoprene. Your body heat warms that water, and the dense neoprene slows heat loss. The suit works, but the mechanism is different, and the warmth is usually less than an open cell suit of the same thickness.

Because the material is compressed and non-porous, water does absorb into the neoprene itself over time — but much more slowly than it would into open cell foam. This means a closed cell suit stays relatively dry inside compared to an open cell suit, which can become waterlogged after heavy use. A drier suit is easier to pull on and off, and it does not retain water weight the way an open cell suit can.

In cold water, many spearfishers layer a closed cell suit with a thin open cell rashguard or add a hood for extra insulation. The closed cell base handles buoyancy control, and the open cell layer adds warmth without adding significant weight.

Thickness and Fit: What Works for Spearfishing

Closed cell wetsuits are typically available in thicknesses from 3mm to 7mm, with 5mm being the most common choice for spearfishing in temperate water. Thicker suits provide more warmth and slightly more buoyancy compensation, but they also reduce flexibility and make movement on land more difficult. Thinner suits (3mm) are better for warm water or for hunters who prioritize mobility over warmth.

Fit is critical with closed cell neoprene because the material does not stretch as much as open cell. A suit that is too loose will allow water to move around inside, reducing insulation and creating drag. A suit that is too tight will restrict your breathing and movement underwater. Most manufacturers size closed cell suits more snugly than open cell alternatives, so measure carefully before ordering.

The seams matter more in a closed cell suit because water moves through seams more readily than through the compressed neoprene itself. Look for suits with glued and blind-stitched seams rather than just stitched seams. Some high-end closed cell suits use taped seams as well, which adds cost but improves durability and reduces water entry.

Durability and Maintenance of Closed Cell Wetsuits

Closed cell neoprene is more durable than open cell in some ways and less durable in others. The compressed foam resists compression damage — if you fold or pack a closed cell suit, it bounces back. But the material is also more brittle, especially in cold conditions. A tear in closed cell neoprene can spread more easily than a tear in open cell foam, so handle the suit carefully and repair small damage immediately.

Maintenance is straightforward. Rinse the suit in fresh water after every use, especially after saltwater diving. Hang it to dry in shade — direct sunlight breaks down neoprene over time. Store it flat or on a wide hanger, never folded or crammed into a bag. A well-maintained closed cell suit can last three to five years of regular use, though the seams and zippers typically wear out before the neoprene itself.

If a seam starts leaking, you can patch it with neoprene cement and a patch kit designed for closed cell material. Open cell patch kits do not work as well on closed cell neoprene because the material does not absorb adhesive the same way. Buy the right repair kit when you buy the suit.

Cost and When Closed Cell Makes Sense

Closed cell wetsuits cost 30 to 50 percent more than comparable open cell suits. A quality 5mm closed cell suit runs between $300 and $500, while a similar open cell suit might cost $200 to $350. That premium reflects the manufacturing process and the material's performance in the water.

The investment makes sense if you hunt regularly — more than a few times a month — or if you dive in conditions where buoyancy control matters (deeper water, strong currents, or long bottom time). If you dive occasionally in warm water and do not need to carry much lead weight, an open cell suit will work fine and cost less.

Consider also that a closed cell suit reduces the amount of lead weight you need to buy and carry. If you are currently using 15 pounds of lead in an open cell suit, you might use 8 to 10 pounds in a closed cell suit of the same thickness. Over time, that savings in weight and the reduced physical strain add up.

Closed Cell vs. Open Cell: The Real Differences for Your Diving

Open cell wetsuits are more flexible, warmer for their thickness, and cheaper. They are the right choice if you prioritize comfort on land, warmth in cold water, or budget. Closed cell wetsuits are denser, require less lead weight, and give you better buoyancy control at depth. They are the right choice if you spend significant time underwater and want to reduce the physical load.

Some spearfishers own both and choose based on water temperature and depth. Others commit to closed cell and accept the trade-offs. There is no universal answer — it depends on where you hunt, how deep you go, and how often you dive.

If you are new to spearfishing and unsure which direction to go, start with an open cell suit. Learn the sport, figure out your typical diving conditions, and then decide whether the buoyancy and weight advantages of closed cell are worth the cost and reduced flexibility for your situation.

Frequently Asked Questions

Do closed cell wetsuits keep you warmer than open cell?

Not usually. Open cell wetsuits trap air for insulation and are typically warmer for the same thickness. Closed cell suits rely on a thin water layer warmed by your body, which is less efficient. In very cold water, most spearfishers layer a closed cell base with an open cell rashguard to get both buoyancy control and warmth.

How much less lead weight do you need with a closed cell suit?

It varies by suit thickness, your body composition, and the specific neoprene formula, but most divers reduce lead weight by 30 to 40 percent when switching from open cell to closed cell. A diver using 15 pounds in open cell might use 9 to 11 pounds in closed cell of the same thickness. Your dive shop can help you dial in the exact amount.

Can you repair a closed cell wetsuit the same way you repair an open cell suit?

No. Closed cell neoprene does not absorb standard neoprene cement the way open cell does. Use a repair kit specifically designed for closed cell material, or take the suit to a shop that specializes in closed cell repairs. Seams are harder to repair than tears because the glue bond is different.

Is a closed cell suit worth it if I only dive a few times a year?

Probably not. The higher cost and reduced flexibility make more sense if you dive regularly. If you hunt only occasionally, an open cell suit will work fine and cost less. Revisit closed cell later if your diving frequency increases.

What thickness closed cell suit should I buy for temperate water?

Five millimeters is the standard choice for most temperate water spearfishing. It provides adequate warmth, reasonable flexibility, and good buoyancy characteristics. Go to 7mm if water temperatures drop below 50°F, or 3mm if you are in warmer conditions and prioritize mobility.