# Is swimming pool water thicker than ocean water? **URL:** \ **Category:** Factual Questions\ **Created:** [August 8, 2001, 11:40pm UTC](https://boards.straightdope.com/t/is-swimming-pool-water-thicker-than-ocean-water/75512 "2001-08-08T23:40:34Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![handy](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@handy](https://boards.straightdope.com/u/handy)\ **Post date:** [August 8, 2001, 11:40pm UTC](https://boards.straightdope.com/t/is-swimming-pool-water-thicker-than-ocean-water/75512/1 "2001-08-08T23:40:34Z")
I noticed going in the ocean after swimming in a swimming pool that the ocean water seems thinner. Is this scientifically so? ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [August 8, 2001, 11:56pm UTC](https://boards.straightdope.com/t/is-swimming-pool-water-thicker-than-ocean-water/75512/2 "2001-08-08T23:56:23Z")
No, the salt water is going to have a higher density, and I can’t think of any reason why the viscosity of chlorinated water would be higher. I assume that you think it’s ‘thinner’ because salt water has a higher bouyancy, making you feel lighter and ride higher in the water. This makes swimmming easier in salt water. ---
**Author:** ![City\_Gent](https://avatars.discourse-cdn.com/v4/letter/c/a87d85/32.png) [@City\_Gent](https://boards.straightdope.com/u/City_Gent)\ **Post date:** [August 9, 2001, 4:09am UTC](https://boards.straightdope.com/t/is-swimming-pool-water-thicker-than-ocean-water/75512/3 "2001-08-09T04:09:48Z")
By ‘thicker’, do you mean denser, or more viscous? ---
**Author:** ![evilhanz](https://avatars.discourse-cdn.com/v4/letter/e/ba8739/32.png) [@evilhanz](https://boards.straightdope.com/u/evilhanz)\ **Post date:** [August 9, 2001, 6:25am UTC](https://boards.straightdope.com/t/is-swimming-pool-water-thicker-than-ocean-water/75512/4 "2001-08-09T06:25:29Z")
It’s hard to know what you mean by “thinner”. But I think you mean easier to move in. I’ll hazard a brief analysis: _Comparison of density_: salt water is denser than pool water which is essentially fresh water with a few disinfectants. Objects in salt water are more buoyant than those in fresh water. Ask any diver. In that sense it’s easier to move in salt water than pool water as an unencumbered swimmer. If you are paddling in a boat, however, it will be more difficult to move the denser salt water. _Comparison of viscosity_: All water has high viscosity. As temperature increases, viscosity decreases (about 3.5% per 1[sup]o[/sup]C). Generally ocean water is colder than than pool water, so it should have a higher viscosity - meaning less maneuverability for anyone in it. I don’t think this is a noticeable factor for swimmers. It’s a more important consideration for much smaller organisms. I opt for differences in **density**. Read some articles by high-performance kayakers for a good discussion of the differences between viscosity and density as they apply to water sports. I am hesitant to link one or two, but a Google search should bring up enough to satisfy your curiosity. ---
**Author:** ![TV\_time](https://avatars.discourse-cdn.com/v4/letter/t/f17d59/32.png) [@TV\_time](https://boards.straightdope.com/u/TV_time)\ **Post date:** [August 9, 2001, 10:22pm UTC](https://boards.straightdope.com/t/is-swimming-pool-water-thicker-than-ocean-water/75512/5 "2001-08-09T22:22:37Z")
I believe it is a general rule that people are more buoyant in salt water than non-salt water and the more buoyant one is the less drag his/her body provides when swimming (less of it coming up against the water during the foward movement in other words) thus it would seem thinner. Generally speaking any aid to buoyancy will make water resistance seem less and will make swimming easier. There was something of a controversy in the triatholon world a few years ago over the wearing of wet suits which help buoyancy thus speeding up swimmers. ---
**Author:** ![woolly](https://avatars.discourse-cdn.com/v4/letter/w/ebca7d/32.png) [@woolly](https://boards.straightdope.com/u/woolly)\ **Post date:** [August 11, 2001, 12:26pm UTC](https://boards.straightdope.com/t/is-swimming-pool-water-thicker-than-ocean-water/75512/6 "2001-08-11T12:26:10Z")
An example of the effect of the bouyancy: Lamb #1 was 4yo and learning to swim. At the local (chlorinated) pool he was just able to swim across two lane widths before he needed support. At one stage that pool was closed and we went to another pool which was salt water. During the session there he swam (dog paddled) three full 50m laps unassisted. The flip side was that he got overconfident with his swimming ability and when we went back to the local pool he jumped in expecting to float and went straight to the bottom necessitating some quick action from Dad.