What is open cell?

The term open cell is widely accepted by manufacturers and divers despite being somewhat of a misnomer. For the benefit of those not familiar with open cell wetsuits a quick explanation will be helpful. Without exception ALL wetsuits are made with closed cell neoprene material, hence the misnomer. For our purposes open cell simply refers to the interior surface of the suit being smooth neoprene without a lining attached. The term open cell is derived from the process of shearing/cutting the neoprene into precise thickness sheets required to produce the different thickness wetsuits. The shearing exposes only the top layer of micro cells (neoprene is made up of tiny cells filled with air) and the neoprene does not become permeable as the name open cell would imply. The sheared surface is smooth to the touch, and each sheet has two sheared surfaces (top and bottom). One of them is left as is, that's the smooth interior of the suit and goes against the diver's skin. The outer surface has a camo pattern Lycra lining applied to it.

The open cell wetsuit interior creates suction against the skin, stopping water circulation inside the suit. Once the suit is properly fit with no loose areas, it creates a seal and no water can enter. This makes the open cell suit much warmer than suits with a lined interior. Generally speaking a 3mm open cell suit will be as warm or warmer than a 5mm double lined scuba suit. With the thinner open cell suit the diver will be just as warm but less buoyant. This means less weight to carry on the belt resulting in added comfort.

Open cell suits require lubrication to put on, a mixture of water with a small amount of hair conditioner in a spray bottle is normally used. The suit can also be put on in the water with no lubrication. Once thoroughly wet inside, the suit slides on and off effortlessly, an open cell suit is much easier to don than a conventional double lined scuba suit. ** Care must be taken donning the suit as open cell is sensitive to cuts with fingernails ** The exterior Lycra is as durable as any lined suit and you can safely pull on it. Open cell is easy to wash/keep clean and is more resistant to bacteria growth than porous lining.

With all the advantages of an open cell suit, you may be wondering why everyone is not using them, including scbua divers? In Europe all freedivers and spearfishermen use open cell suits. In general divers in the US are conservative when it comes to wetsuits. For scuba shops double lined wetsuits are an easy sell, so they stock and promote them exclusively. This and higher cost of open cell suits slowed the transition. Freedivers who spend longer periods of time in the water, and require more warmth and comfort were first to adopt open cell suits in the US. The bottom line is, if you try an open cell suit you will never go back to double lined wetsuits.