LIVE TEST: Silicon Drysuit Seals are a reality

Some new dive products are just cool, some are just very practical, but for drysuit divers, the Integrated Silicone Seal System (I.S.S.S) | by WaterProof and Si Tech is a true revolution. For those who have silicon seals, it will change your experience of diving dry. We have shown the seals to dozens of other divers donning their suits and you can see their minds churning about when they can get some. That is why we gave it a best in show award at the 2009 DEMA Show ( (Note: The live testing that we did is only with the silicone wrist seals as our suit was not currently equipped to handle the neck seals.)


Our live tests were done on wrist seals on Whites Fusion Tech drysuits with Si Tech rings and revealed that the reality was even better than the promise. When you slip on a silicon seal, first your have to you get over how easy it was to get on, then you notice the gentle hug of comfort on your wrists and neck. It feels like you are wearing a soft sweatband to do a workout instead of a constricting seal. After a minute or two I had to look at my wrist to remind myself that the seal was still there. The silicon seals were so comfortable we were both almost afraid to dive them; fearing that they would surely leak. They did not. The silicon itself has a soft and almost sensuous feel to the touch. You can throw away the bag of talcum powder – these are simple to don.

All of our tests, with both cone and tube style seals were done with them untrimmed. Unlike latex seals, there was just no reason to trim the silicon seals. They felt un-constricting right out of the box. With latex seals, I have always been ambivalent about trimming them. Besides running the risk of a nick in the cut that may later tear, trimming my latex seals has always shorted the life. I was resigned to stretching them and using new latex seals a bit extra tight until they wore in. For me this meant a day or so of “numb thumb” or carpal tunnel like symptoms after each dive. So I am can be literal in giving silicon seals two happy thumbs up.

Besides the extreme comfort of the silicon seals, it is expected that silicon seals will not degrade and deteriorate from many chemicals (encountered during normal recreational dives) or ozone and should have a much longer life than latex seals. They have an greatly increased tear resistance than latex. The video we took at DEMA shows a woman stretching a silicon seal while digging her long and sharp nails into it with no damage.

Now do you want the bad news. But do not worry, the bad news over the long run can actually become good news too.  Here it is. You cannot glue the silicon to the suit. You can only have them with a ring system. Getting the ring systems on your drysuit gives you a great advantage even if you do not use the silicon seals. It means that you never again have to worry about aborting a dive on the inevitable day that your seal blows while donning for a dive. You also do not have to change seals well before they are ready in order to save you from blowing the seal on a diving day. When you do rip a seal attached with a ring system, you just swap it out on the spot in minutes. No more saying, “I cannot dive for two weeks because my suit is in the shop for seal replacements.” And no labor charges for replacing seals, you just swap them yourself. The silicon seal is also made with a lipped edges so that easily fits and stays in the wring system.

WaterProof designed the silicon seals in partnership with Si Tech for their current wrist ring systems. They will also work with other ring mount systems. The wrist seals are not that much of a problem as many drysuit manufactures offer ring systems as an option. The wrist ring systems can be easily added to most suits.

The neck ring is another story that may slow the adoption of the silicon neck seals. Currently Si Tech “Nek Tite” Drysuit Neck Seal System is the only one available that will allow you to use the silicon neck seal. DUI, which currently has a different type of the ring systems, their patented ZipSeal system, told us that they should have a silicon ZipSeals available before the next DEMA show in November 2010.

On our first inspection of the Si Tech Nek Tite system looked like it was thin and flexible enough. There are many variables in drysuit designs and we cannot yet tell how the comfort of a particular suit will be affected by installing this system. This is especially important for the Whites Fusion which is the most flexible suit on the market today. And sadly one of our testers has reported that the current version of the Nek Tite system was in fact “extremely uncomfortable when installed in a Whites Fusion. The edges of the ring dig into your shoulders if you try to move your arms as well. It really took away from the whole idea and feeling of the Fusion.”  We hope that Si Tech can improve the comfort to open the door for divers to have the same comfort on their neck seals.

Bob Stinton, DUI’s VP of engineering is one of the most thorough persons we know when if comes to new products. He take a more cautious approach to pinning the revolutionary medal on silicon seals. As mentioned, DUI is working to put the new silicon seals on their ZipSeal system. Bob was generally agreeable about the comfort, tear resistance and the resistance to ozone. He said his tests indicate that the seal will still tear when nicked like latex. While he agrees that the storage life will be much longer than latex, he is not sure how this will translate to working life (number of dives).

Whether or not the silicon has a memory will affect this and DUI is working on testing this. Stinton pointed out that those with mild latex allergies should not have problem diving seals made from latex because the allergenic protein is removed from all latex dive seals and they are considered hypo-allergenic. However our internet searches revealed at least one medical report of diver going in to anaphylactic shock while diving from a reaction to a latex seal. 

Bob also said the latex seals when trimmed to fit are very comfortable. He chuckled, though, when he said that this is easy to say for people, like himself that have pay for their own seals. He can afford to trim his to the perfect size and shorten the life. We found the silicon seals seem as comfortable as trimmed latex without trimming the silicon and easier to don and doff.


  • comfort – comfort – comfort
  • No latex allergy.
  • 40% more stretch than latex
  • chemical and ozone resistance
  • superior tear resistance even when nicked (see video)
  • easy to get on and off
  • replace on the spot and save the dive
  • come in colors besides black


  • You cannot glue them to the suit. You must use the Si Tech (or other ring mount system).

 Even if the long term usage does not prove the claim of a greatly extended life for the silicon seals, there is no denying they are joy to put on, take off and wear during the dive. Even if you have to change them at the same time you would a latex seal you will have had a much nicer year of diving silicon seals.  We give seals 5 out of 5 stars for innovation and changing the drysuit experience. However, we will have to add a cautious, wait and see if Si Tech can improve the comfort of the Nek Tite system and how it fairs as in in other drysuit models.

Although most drysuit divers have heard of Si Tech, most have not heard of WaterProof before this. These two Swedish companies are very innovative and should be on your radar screen. WaterProof has unique form fitting wetsuits and new drysuit with an amazing 3 dimensional mesh liner that requires no undergarment for cold water.

We thank WaterProof, Si Tech, and Whites for supplying the demo seals for this article.