Time value of a wetsuit?

Believe it or not, there are two different questions/answers to this.

In general, I find that a wetsuit gives me 10s /100 more speed when compared to not having one.  I tested that several times in a pool.

BUT, if I compare my OWS with a suit, to a pool swim without a suit, it's about the same.

For me, I can safely assume I can achieve my pool swim times during an OWS, if I have a suit on.

BTW, I have heard that the better swimmer you are, a suit provides less of an advantage.  IE, a pro might get 5 seconds faster, as a beginner swimmer with poor form, could see 20 or more.

I'm a strong swimmer (or at least I was until a bike accident in June screwed up my shoulder...).  Before my first tri this season, I tried out my new wetsuit in the pool (no way to swim in OW before raceday).  I think I was around 10-12 seconds per 100 yards faster for the same effort-level.  I was swimming around 1:25 pace without trying- normally that would be a pace I would be working decently hard to make.  I've done an IM distance swim in 59 minutes and change (around 1:23/100 yards) with a wetsuit and I've done that distance in the pool without one (though I was less swim-fit when I did it in the pool) in that case, I swam around 3600 yards in an hour (total time around 1:11?). 

While a bad swimmer will get more of an advantage from a wetsuit than someone like me, a wetsuit only helps so much- if you can't swim well and haven't been swimming enough, there is no wetsuit in the world that is going to let someone like that beat someone who is a strong swimmer with a deep swim history (like being on a swim team in high school), even if the swimmer hasn't been swimming much.  You still need to do the work- a good swim base+ a correctly-fitting wetsuit (many wear one's that don't fit)+ comfort in the open water= greater chance of strong swim times.

Mouse -- more than the speed question (well answered by others), what I really like about the wetsuit is the lower heart rate, and lower effort, for the same speed.  A well fit wetsuit greatly increases the ease of holding any speed, giving you more energy for the bike & run.  

Hope this helps,

gordo