USAT’s age group rules, make the wetsuit cut off water temperature 78 (25 C) degrees. This means if the water is above 78 degrees wetsuits are not allowed in order to be eligible for awards in the race. One can still use a wetsuit up to 84 (28 C) degrees but will be ineligible for awards. 84 or higher no wetsuits are allowed period. For professionals on the ITU level the wetsuit temperature cut off is 68 (20 C).
To wear a wetsuit or not to? That is the question! There are no rules stating you must wear a wetsuit. There are many top swimmers who race in the ocean that never use wetsuits and race in water that is often under 68 (20 C). These swimmers however train their bodies to be use to cold water.
Most triathletes train in pools and the majority of pools are 78 (25 C) or warmer. As a result, water even in the low 70’s can feel cold.
Wetsuits are thus a good option to prevent getting chilly if not adapted to swimming in cold water. They are also useful to wear at the start of a race, when it can be cold, in order to keep warm. It is important to have the body warm to start a race to get right into a strong pace. Standing around shivering from the cold is less than optimal for a strong start. (I have made that mistake.)
In most cases a wetsuit will actually make an athlete faster. Wetsuits will allow for more buoyancy in the water. This then means that an athlete doesn’t have to expend as much energy in supporting the rest of their body and thus can put more into forward propulsion through the water.
What is the best wetsuit? There are two main types of wetsuits, one option has full sleeves, the second option is sleeveless. Sleeveless wetsuits will allow for more shoulder flexibility which may be important if you lack shoulder mobility, or maybe you would just feel more comfortable in a sleeveless suit. The issue is that it can feel very cold for many especially when the water drops into the 50’s (55 C).
A full sleeve wetsuit will keep you warmest. Using a full length wetsuit may mean that there is a lack of shoulder mobility. Many of the top wetsuits for triathlon use a thinner and more flexible material through the shoulders. Lots of full length wetsuits also have gripper type panels on the forearms designed to for gripping the water better.
What is the best suit for you then? The one that works for you! Try them on. If possible, swim in the wetsuit before you buy it. Make sure they are as tight as you can get them. Excess room in your wetsuit will fill up with water and slow you down. Baggy spots in a wetsuit can also chaff which is never fun. At the same time you want to have as much flexibility as possible to allow for your stroke to feel natural.
I’m a big fan of some of the wetsuits that have air bubble type panels through the chest, torso and thigh regions. This type of bubble technology is great at providing more buoyancy in the water. Brands such as Orca and Xterra use this type of technology in their top suits.