Surface Swim

[TSandM]

In addition to everything already listed, you have your BC fully inflated at the surface, which increases your frontal profile and therefore increases drag.

Snorkels DO increase dead space -- it is really not a great idea to exert yourself while breathing through one. If you have gas in your tank, you are better off surface swimming facing down while breathing from your reg. I surface swim on my back, and use the gas tank in the sky

 

[g1138]

Surface Tension


Bob

Hmmm not as scientific sounding as I had remembered in 7th grade. Don't I feel silly now

 

[DivemasterDennis]

You observation is correct. It takes less energy to move yourself the same distance at the same pace beneath the surface than it does to move you at the surface. Ask any submariner- its true for submarines and its true for scuba divers. You also get the full benefit of a longer kick for locomotion at depth compare to the surface. Good for you for noticing this fact. Other responses are creative but not all on the mark.

 

[TMHeimer]

All good replies. I try to relax on my back with snorkel. Of course if you hit an enexpected current/tide that's not advisable--you motor and the heck with it.

 

[CuNanoTube]

I think the largest factors would be a larger profile due to an inflated BC and a shorter kick. Surface tension does not strike me as a major factor as the surface tension bonds are very very weak, so weak that the effect should be negligible.

I once did a 500m surface swim to a dive site, followed by a 500m swim back. It took about 40 minutes each way and was quite tiring. Both of us swam on our backs, though we did notice it was easier when face down. (probably due to the bladder being forced under increasing surface area)

 

[RTee]

Good points brought up by all. My preference for deliberate swimming to cover distance is surface swim and doing so on my back as I can breath normally and not through a snorkel or reg/tank which I prefer using underwater. I think it is also pretty hard to compare one type of swimming to the other (surface and underwater) and the reasons are fairly simple.

First, I think that when swimming face down, the fins are much more effective underwater than on the surface as you can go through the full range of motion. I think the only way you can get something similar while controlling fully your fins at the surface is to do so on your back.

Secondly we tend to swim very differently underwater. Scuba diving is supposed to be relaxing with the least amount of physical activity therefore we normally strive to swim slowly and pace ourselves. Frog kicking is a prime example...deliberate kick then glide and we restart the process. For those who prefer the alternative kicks...slow and steady. Rarely do we swim underwater with the same intensity as we would do on the surface to cover a given distance or swim on the surface as lazily as we do underwater. Therefore perhaps it is natural to feel that swimming at the surface is more tiring.

 

[Nemrod]

Surface Tension


Bob

I know you know this but surface tension phenomena has nothing to do with swimming on the surface. It might for a water bug but not a human. I can swim faster on the surface than under the surface. You (OP) got tired because you were probably hurrying yourself along and as someone else mentioned, using different muscle groups.

The snorkel, I dunno, I have done some fin tests using a snorkel and swimming different fins against each other, After a couple of miles you think if there was much CO2 retention I would have noticed it huh?

N

 

[Hatul]

As far as the work of breathing through a snorkel, there must be more to it than just dead space, because I find it easier to breathe through a larger diameter snorkel. By dead space argument you'd expect the opposite. I think it's a combination of extra dead space and breathing resistance through the tube. After all with a little bronchospasm it gets pretty uncomfortable to breathe, and here you're pumping a lot of air through one narrow tube.

Also if using the snorkel in prone position there must be some work against the water pressure gradient from the surface to mouth.

Adam

 

[ItsBruce]

Thanks, everyone. At least it was not my imagination that I was working harder and getting more tired while on the surface. Also, I had not thought of the fact that the inflated BCD increases drag, and probably a lot.

After I covered about 1/3 the distance, I rolled onto my back, which I, too, prefer.

 

[MaxBottomtime]

Unless I'm snorkeling I always make surface swims on my back without a snorkel. There is plenty of air to breathe if you're facing up. Also, while on your back, your fins remain underwater, giving you more thrust. Snorkeling, they tend to come out of the water, wasting energy. Plus, your tank is underwater that way reducing drag.