Significantly faster in a deeper pool?

Sounds familiar - I too am quicker in a deeper pool.  I have two to choose from, but I end up at the 3'6" one most often since it's closer.  However, whenever I get in the 9' pool I just feel quicker and the clock supports that.  I had a swim coach tell me once that you'll be faster in a deeper pool because of less disturbance from water coming off the bottom but I'm not sure if that's true.  It may just be a mental thing for me - if I feel like I'm going to be quicker in the deeper pool, it's easy to make that a self-fulfilling prophecy.

I'll be curious to read what others have to say.

Although I can definitely paddle a canoe faster in deep water than shallow, I personally think that water temperature was the bigger factor. I definitely swim at LEAST 5/100 faster in comfortable water, just like I run faster in comfortable (vs. too hot) air.

Off the top, it's probably the water temperature.

Our indoor pool tuned up for the aerobics class flirts with low 80s and that's a struggle. The outdoor pool that's being neglected right now is running 70 or so and it's awesome. I love that pool, but it's closed a little longer until the weather gets a wee bit nicer.

Secondly, you will be faster in deeper water. One of the reasons that in the Olympics in Beijing, the swimmers were crushing records. The deeper the water, the further the water has to travel away from your body before coming back at you. There's more space for the water to spread out (in horizontal and vertical directions) eliminating the immediate chop and bounce. 

There was a great "in depth" on the construction of the pool and how it was designed for speed. Really cool stuff there.

Interesting!  I do notice the push back from the current in my shallow pool when I turn at the wall.  Never thought about how a deeper pool changed that. 

My first guess is water temperature BUT...

My friend who is a lifeguard told me at my first indoor tri to take the outside lanes because they are faster. Now, he's not a physicist but he explained that the water splashing back to you from the walls can slow you down. By this logic, wouldn't that also apply to a shallow pool?

Along with the temperature and the depth, the aquatic center pool probably also has more sophisticated gutters and lane lines.  Fast pools tend to have enormous gutters that can take in a lot of waves and reduce churn and larger lane line dampen turbulence from  lane to lane.

Depth, temperature, and lane width are regulated in NCAA competition.  Lanes must be 7' across, depth must be at least 4' and temperature must be between 79 and 81 degrees.

http://fs.ncaa.org/Docs/rules/fielddiagrams/swimming_diving.pdf

(warning that is a really boring read)

Hmmm. This flies in the face of Olympic swimming specifications for swimming pools which mandate a specific minimum depth.

My admittedly cursory understanding is that shock waves reverberating off the bottom of the pool may have both a propulsive- and reductive- effect of swim velocity depending on the shock wave action. Bottom line: It changes times.

Interesting.

I did consider that my gym pool is maybe 25 meters, but then there are inconsistencies in the paces when converting the pool distance to yards.  But the feel of that pool was so much smoother, even flip turns were much easier makes the turbulent water theory of the shallow pool sound possible. 

You're getting faster just means I have to work harder.  In my shallow and hot pool, geez can't I catch a break...

I routinely practice in a pool that is less than a metre deep, has no gutters, is probably closer to 90F than 80F, and that a swim team practices in at the same time. No lane lines.

I'm faster in the ocean, even without the flips and push-offs. Come to think of it, I'm faster just about anywhere else. Significantly.

That would mean you have to race a tri this year doesn't it Mark? 

So it seems like I am experiencing the stark differences in ideal swim conditions; shallow, warm pool with narrow crappy lane dividers vs ~7 feet deep, cooler water, competition pool with gutters and nice wide lanes.  Even flip turns were easier in the competition pool once I got used to the distance to the wall...

Too bad my A race is in conditions closer to the gym pool, a warm, shallow, choppy river with irregular current patterns.

Yes, I should have clarified that there was more pool (kids' area or whatever) on the other side of the lanes.

This has been a fascinating read. I had no idea about the whole science to gutters, lane dividers, etc.