At What Water Temperature Do I Need a Wetsuit?

For many open water swimmers around the world, a wetsuit is an essential piece of gear they need for all their training and racing adventures. These tight-fitting body suits, usually made of high-tech, black neoprene and ranging in thickness from a super thin 0.5 millimeters to a robust and toasty 6 millimeters or more, can make swimming in cold water a lot more enjoyable. They work by trapping a thin layer of water between your skin and the suit. Heat from your body quickly warms that water into an insulating layer, and provided the suit fits correctly, you’ll feel comfortable in short order.

Wetsuits can be enormously helpful for heat retention, and they aid in buoyancy. This feature can be especially beneficial for less experienced swimmers who struggle to find the most efficient body position on their own. The gentle pressure the suit exerts on the body can help support you as you swim and lift your legs and make you just a little sleeker. Think of it as being the swimming version of wearing compression socks or tight cycling shorts when running or biking.

When to Wear a Wetsuit

If you’re just starting out with open water swimming or triathlon, you may be wondering when you should don a wetsuit. Much of the time, that’s a personal decision and there can be a wide range of answers to that question.

For some people, when the water dips below 80 degrees, it’s time to suit up in a full wetsuit. Other swimmers never wear a wetsuit, even when the water is near freezing. It all depends on your ability to tolerate the cold, your experience level, your goals, and whether the use of a wetsuit is allowed or required to participate in a specific event.

USA Triathlon has set some parameters around the use of wetsuits for its events. First, when the water dips below 50 degrees Fahrenheit, the open water swim portion of the race will be outright cancelled, because USAT deems water this cold unsuitable for open water swimming even with a wetsuit. When the water temperature measures between 50 and 65 degrees, wetsuits are strongly encouraged, and some races may require their use.

Between 65 and 78 degrees, it’s typically the athlete’s choice of whether to wear a wetsuit.

When the water creeps above 78 degrees, participants can choose to wear a wetsuit, but wetsuited swimmers competing in events where the water temperature falls between 78 and 84 degrees are not eligible for awards. When the temperature exceeds 84 degrees, wetsuits are not allowed as a safety precaution against overheating.

USAT also stipulates that wetsuits used during a sanctioned event cannot be thicker than 5 millimeters.

USMS also has set guidelines around the use of wetsuits in its sanctioned events. These rules are spelled out in the Rule Book, and state that wetsuits may be permitted or required at the race director’s discretion in most instances. However, if the water temperature is 78 degrees Fahrenheit or higher, wetsuits are not allowed.

As with any piece of gear, it’s best to train with the wetsuit you plan to wear during an event; changing things up on race day is never the best idea.

Finding the Right Fit

Wetsuits come in a wide range of styles and sizes, and new companies are constantly cropping up, offering new innovations. But one thing hasn’t changed: Finding the right fit for your wetsuit is paramount, and you may need to try a few styles and brands until you find just the right one.

Wetsuits that are too-tight have been associated with the possibility of developing swimming-Induced pulmonary edema, a dangerous condition in which fluid backs up into the lungs causing coughing, difficulty breathing, and coughing up pink foamy sputum. Though the condition typically resolves on its own in time, it can put a major damper on your day and usually requires medical attention.

On the other hand, a wetsuit that’s too loose won’t offer you much heat retention benefit as water rushes through it and doesn’t get trapped to create that insulating layer. A baggy wetsuit can also create more drag to slow you down as you swim.

Nailing the fit can be tricky but trying it on can help guide a good choice. A wetsuit that fits properly should not restrict your movement or cause pain. You should be able to move your arms and shoulders in their full range of movement and not feel any pinching along the shoulders, in the armpits, or around the neck. It also should not feel like it’s riding up in the crotch. A well-fitted wetsuit should feel like a second skin that moves with you, not against you.

Wetsuits designed specifically for triathletes and swimmers are different from the types of suits intended for water-skiers and scuba divers. Triathlon suits often have thicker panels along the trunk and thinner neoprene across the shoulders and arms to improve flexibility and range of motion. If you’ll be using your wetsuit for training and racing triathlon, look for ones that are labeled as triathlon suits and that are less than 5 millimeters thick.

SwimOutlet.com has a handy wetsuit shopping guide online that can help you work through some of the specifics of finding the right fit for your next race or training session.

Looking for more great information about swimming? Check out our Swimming 101 guide featuring swimming pool and stroke basics, how to start swim training as an adult, and more.