All three of these are good questions and worth addressing, because non wetsuit legal swims seem to be on the on the rise.
If you paid attention to the Ironman World Championships this past weekend, then you noticed that the swim was once again not wetsuit legal. Kona is almost always too warm (over 76.1℉) to allow wetsuits, which means that triathletes resort to wearing a swimskin instead.
For those of you who do not know, swimskins are a 100% textile, neoprene free cover that goes over ones tri suit and extends from the knees to the shoulders with no sleeves (in fact if you have sleeves on your tri kit which is actually becoming quite popular right now, you must roll up your sleeves for the swim).
Since they do not have neoprene, they offer no buoyancy or help with body position, but that does not mean they cannot improve you swim times. Quite the opposite.
The biggest benefit of wearing a swim skin is that they decrease drag. Your body, even if you shave your chest or compress your breasts, is not the most hydrodynamic and creates lots of drag. If you put an absorbent tri shirt on then the drag increases further.
The swimskin smoothes out your body’s ripples and decreases drag.
The special textile material and covering also reduces friction in the water as well as water absorbency so you are not weighed down as much when going through the water.
While it is hard to conduct a good scientific study on these, several case studies have tested out swimskins and shown significant benefits for their use.
The average savings were between 2-4 seconds per 100m, which is significant when added up over 2.4 miles.
However, these case studies were done on pretty elite age group athletes who typically swam 1:20-1:25/100m without a swimskin.
Despite a comprehensive search, I have yet to find a good study performed on typical age groupers.
The two top selling swimskins are the TYR Torque and the Blueseventy PZ3TX, which just got upgraded to the PZ4TX.
Both are excellent suits and provide similar time savings in tests, so the purchase decision comes down to feel. I personally prefer the Blueseventy because I cannot feel it at all when swimming.
It is tight and conforming when I first put it on but when I get into the water, I barely notice it. The PZ3TX also seems to last longer from both personal experience and those whom I have asked.
The TYR Pro (which is more expensive than both the Elite and Light models) seems to last 5-6 races while the Blueseventy seems to last 10-15 races before the material begins to fade.
Both swimskins are around the same price point of $300-350.
So should you buy one? If you know for a fact that your swim is going to be too warm for a wetsuit and you want to shave every second off your swim split then yes, a swimskin would be a good investment.
However, if you are at the back of the pack and merely want to do your personal best rather than podium (which is 100% fine and perfectly acceptable to do), that $350 might be better spent elsewhere.