Dialing in your trim in a drysuit sdi tdi erdi electricity physics khan academy


Whether you’re a prospective, or new, dry suit diver – you’ve likely heard a few outrageous stories about the potential challenges that come with diving a dry suit, specific to body position or “trim.” If you’re not sure what we mean by body position or “trim” while diving check out this article.

So, maybe you’ve heard once you dive dry, “there is no way you can reach your valve(s)” or a dramatic story of a diver having too much gas in their feet and rocketing towards the surface upside down. Sure, each of these scenarios is possible but they can be easily avoided with a combination of a proper fitting suit, adjusting your tank position and weight placement, honing in on your dry suit diving skills and technique, and gaining more experience. In time, you can dive a dry suit just as easy as a wetsuit.

As a diver who dives dry 90% of the time, I can honestly say a proper fitting dry suit is the best equipment investment I have made to this day. Like many divers, I started diving dry in a suit that was not fitted properly and found it to be a little challenging. Everyone is shaped different and few people match up to an “out of the box” suit for a perfect fit, and there is nothing wrong with that.

Diving a dry suit that fits you properly will make your future dry suit dives so much easier and comfortable. It will allow you to manage less gas in your suit and make it extremely easy to vent gas when the exhaust valve is placed in the ideal position for your body. In addition, a proper fitting suit will allow you to place your arms out in front of you to hold that “perfect trim” position and give you enough freedom and flexibility to reach your valve(s) behind you.

Let’s start with tank position. Just like diving a wet suit, your tank placement can have a significant effect on your trim in the water. Do you feel like you can’t get your feet up? Try sliding the cam bands down on your cylinder just a bit or if you have floaty feet, try the opposite. Doing so can create a fairly drastic shift in your center of balance by just moving your BC cam bands up or down a few inches.

On to weight placement. Weight placement is even more critical in a dry suit than diving wet. This is primarily because you are likely to use more of it. If you typically wear all of your weight on a weight belt or in a weight integrated system on your waist, adding the additional weight you need in a dry suit to this area could have detrimental effects on your trim and drag your hips down. To counter this, consider using trim pockets (either built in or aftermarket pockets that weave on to your cylinder cam bands) to help distribute some of the additional weight further up on your body for better balance.

Diving a proper fitting suit can help reduce having excess gas trapped in your legs and feet area. In addition, many modern suits have retaining ankle straps designed to keep excessive air from entering your boots if you don’t use a separate boot style shoe. If your suit did not come with ankle straps, you can purchase aftermarket “gaiters” or simply use bungee cord to help keep the excess gas out of your feet. If you continue to have “floaty feet” issues, you may also want to consider switching to a heavier fin or go back to adjusting your tank position and weight placement.

Well, my goal with this piece is to discuss methods to dial in your trim while diving dry so with that in mind, I tend to lean towards the route of using your BC for buoyancy and adding gas to your dry suit only to offset squeeze and for warmth as needed.

Why you ask? Having too much gas in your suit can make it difficult to maintain control and proper body position while diving; whereas having just enough gas in your suit will allow you to determine where that gas is placed to support better trim and control.

With practice and experience, managing your dry suit and BC will become second nature. On the few wet suit dives I make each year, I find myself going through the motion of trying to add a small amount of gas to my suit when I get a little chilly, only to laugh at myself when I realize I am not in a dry suit. In time, diving dry can become just as easy as diving wet and the skills, such as adding and venting gas from the suit, will become second nature. My best advice on this, work with a qualified instructor and get out there and practice!

Proper trim in a dry suit can be a challenge in the beginning. Before purchasing additional equipment as a quick fix, allow time, practice and patience for your body to adapt to adding a dry suit in the mix. Remember, tank and weight placement, along with a proper fitting suit are essential to dialing in your trim while diving dry. For more information or to find a SDI Dry Suit diving instructor near you, click here!