Anyone got a reliable estimator to predict an OW swim (w/wetsuit) to a pool swim time?
I think the best thing to do is to use this formula:
Take your time for an all out 100m swim ( in a lcm pool, of course), multiply that by the OW factor of 1.05, add the “stroke efficiency factor” calculated below, divide all this by 100, mulitply that by the distance in meters of the ow swim, add to that for each 500 meters of the swim - ‘fitness factor’ (also calculated below as well). Once you have this ‘initial average pace + degeneracy and fatigue constants’, choose a number for the surface conditions. 1=glass, 5-O.H. swells with a nasty cross chop. Add this to your average pace by Suface condition number * distance (m) / wind advantage. Consider the wind advantage to be +1 if it is against you at least 10 knots, or -1 if it is at your back and >10knots. If it is a circle course use +0.5. This should give you a rough estimate of you time using a wetsuit in open water conditions.
'stroke efficiency factot"
take the number of strokes per lenght ina 25 yd pool, subtract 10 and use this number.
‘fitness factor’
if you train between 0 and five hours EVERY week, use -3
if you train between 5 and 10 hours Every week, use -1.5
if you train between 10 and 15 hours every week, use 0
if you train more than 15 hours or swim more than 25k yd, use 1.0
I hope this helps. It iis usually predicts my time to within 2"/100m
Yes. +20% to -10%. IOW it depends. Some people are faster with a wetsuit (but not all), while some people have very good flip turns in the pool so have relatively fast pool times. So it depends on whether you are the type of person that benefits a lot from a wetsuit (poor body position, heavy legs, weaker swimmer, etc.) and whether you are good at turns in the pool.
Here’s an example. My wife kicks my butt in the pool. Generally 5 seconds per 100 yards. We both use the same wetsuit and she has never had a faster race swim time in the 20 or so tri’s we’ve done. Quite simply she has better flip turns and I benefit more from the wetsuit due to poor body position/heavy legs.
Swim courses are so random in length too, that is hard to compare. I did 3 races one summer, close together, 3 different swim lengths, but my times indicated my fastest pace was in the longest swim, and slowest pace was in the shortest swim. Hmmmm…?
Best estimate? It’s a wash. Pool pace = race pace with wetsuit.
consider most RDs measure ow swim courses about as accurately as a dog pisses on a fire hydrant.
In all fairness, don’t you think it’s a little difficult to measure out a swim course exactly right while bobbing around in a couple boats or kayaks in the short time that RDs have between dawn and the start of the race to get a swim course set up? The fact that swim course distances are more or less guestimates in most races is just part of the fun of triathlons.
lucky
I say that when my swim split in a race sucks. “No way I am that slow, must have been measured wrong” I say. When my split is a little too fast for me, I acknowlege the precision of the course measurement. Once I swam a 16:20 for a 1500m at an olympic distance race. That race was laser sighted and GPS verified as far as I am concerned (never mind the fastest swim was something like a 13). It was the Worlds Qualifier in Claremont, so it had to be accurate…right?
I had a theory about wetsuit vs. pool 100m pace differentials, but every time I race in a wetsuit legal race, someone blows it away. Some people are alot faster with them, others it doesn’t help so much. Usually the better the swimmer, the less it alters the time. Usually…but not always…
I was +5 minutes in the WF Oly swim.
Wow, are you kidding me? I knew I disliked the swim leg for some reason.
Lucky,
Interesting theory, but it completely ignores the crucial importance that barometric pressure plays during arm recovery. Higher humidity means the arm is recovering through denser air, and so must fight more resistance. In a climate- and humidity-controlled indoor pool, the resistance is always consistent. Thus an extra conversion factor must be incorporated into your equation.
Rookie mistake, friend. No harm done.
Nice 
I was also thinking about the phase of the moon as well - changes tidal currents and such, right.
When I was voluntering at the Charlottesville Triathlon (Mid-Atlantic Regional Championships) back in the late 80’s and early 90’s we used a surveyor to set our course. It was a triangular course and ended up pretty damn acurate according to the surveyor. It was within a few meters of either 1/2 or .9 miles. We had both length races at different times of the year in the same place. In all the races I’ve ever done since I’ve never seen a surveyor used to measure the course. It can be done!!