I'm really starting to feel strong and fast in open water. In fact, I'm starting to wonder if, for as strong a swimmer as I am, a wetsuit is necessary if the water temp doesn't require one. I spent some time researching... what do the pros do? It seems like there are plenty of times where they choose not to wear wetsuits when the amateur field wears one. But it looks like it might only save about 10 seconds or so in transition (if you know how to get out of your wetsuit quickly). Does a wetsuit account for more than 10 seconds in the swim? Hmmm... (I hope you can tell by now that I'm just thinking out loud.) Ultimately, I think that the difference is really pretty negligible, and I really like swimming without a giant rubber suit on, so as long as the water is warmer than 70, I'm going without the wetsuit. I love swimming, and I love doing triathlons - saving a debatable couple of seconds for the sake of sacrificing some of the fun of racing just doesn't seem worth it to me. So... no wetsuit for me!
Now, let me be clear - racing without a wetsuit is not for everyone. Gered asked, "Should I swim without a wetsuit too?" My answer for my good buddy would be a resounding "NO." The thing about wetsuits is that they provide a increased rate of return for slower swimmers. As a faster swimmer, I have a solid balance from head to toe. Meaning my legs/feet are fairly higher on the water than those of most people. A slower swimmer (Gered) whose legs hang a little lower in the water, therefore, reaps significantly greater benefit from the added buoyancy of a wetsuit. There are other efficiencies forced upon your body if you are a weaker swimmer that center around the limited range of motion that comes from a wetsuit as well. But stronger swimmers already move within the proper range of motions, so the elastic-y sensation that comes from swimming in a wetsuit may just be annoying (which I think they are).
All this to say that, bottom line, a wetsuit may make a difference of 1-2 minutes for a weaker swimmer, while the difference for a stronger swimmer is likely closer to only 30 seconds. When you also consider the fact that a wetsuit free transition saves you about 10-15 seconds (if you could otherwise strip down quickly), the difference for someone like myself might only be 15-20 seconds (to me, not worth the sacrificed enjoyment by wearing a wetsuit). For someone like Gered (if it takes you 21+ minutes in an olympic swim distance), the time difference - even including the time to strip down - is probably worth the sacrificed enjoyment of swimming without a wetsuit... assuming you even enjoy swimming without a wetsuit anyway.