While I was working on my previous column about the relationship between floating and swimming, I couldn’t help thinking about another relationship: Women are different from men.

Wow, what news! Especially to someone who has been married for almost 40 years – to another swim coach.

Well, it is a fact that females float on their back more horizontally than males. Why? Women have more subcutaneous (under the skin) fat than men.

This fat is spread throughout the body and thus lowers their center of buoyancy (COB), which is below the lungs, closer to their center of gravity (COG), which is around the belly button, making it easier to minimize the natural rotation of the latter around the former.

Without subcutaneous fat, the male’s center of buoyancy is higher, and thus there is a greater distance from the COB to the COG.

This means that when a male attempts to float horizontally on his back, the rotation caused by the COG’s natural tendency to move around and under the COB creates a momentum that pulls the whole body under, which can panic an inexperienced or uneasy swimmer.

So, what are the implications of this exciting fact?

It means that one should begin to attempt a horizontal back float from a vertical position. This can be done by standing in shoulder-deep water and leaning back, but probably best in deep water, holding vertically against the side with arms spread wide before leaning back.

With the COG already under the COB, there is no rotational momentum to prevent the male from his natural tendency to float, but his position is vertical.

If the male keeps his arms and hands under water and moves them up and behind him, he raises his COG and floats more horizontally, reversing what happens if he tries to start horizontally.

And of course, this happens easily and naturally for the female who starts to float from a vertical position.

As I declared initially, men float differently from women, but if they both start vertically to float on their back, that difference can be minimized.

Dr. Bob Colyer of Bluffton is an actively retired college professor, coach and author of “Swim Better: A Guide to Greater Efficiency for Swimmers & Instructors,” directed primarily to non-competitors. bobcolyer@yahoo.com