It slipped my mind until this morning, but at the Chisago race I had the opportunity to break out some dolphin dives.In general my thoughts on dolphin dives up until now (and really continues to be) if you don't know how to do them, or don't do them correctly it's probably slower than just swimming.
Here's a link where Sara McLarty demonstrates dolphin dives in a pool. The narrator talks about it - he says the same thing about doing them correctly, though I think he should stress, if you're not doing it right, it will slow you down.
I will admit that I do not really do much open water swimming beyond races, you could go so far as to say I don't do any, and that would be pretty much accurate. I definitely don't carve out time for open water swims. You need a buddy system, it would be even better if you had someone on land or in a kayak to stay with you, in MN the water is usually freezing cold (not this year though.) Due to total lack of practice, I was quite surprised when I found myself doing one.
Here's my general take on a swim start. I've never had a deep water start, so all of my races to date involve running into the water (usually at full speed) diving in when the water gets to just about knee height and then taking off swimming.
Go back and watch the video, she is doing dolphin dives in water that is
about waist deep for what looks to be about 15 yards. In a beach
setting that has a very long run-in (i.e., it's shallow for a while) you'd probably have a great need for
this. In my experience this isn't a reality. Most races start in areas
that get too deep too quickly to effectively pull this off. I'd say if the water is any deeper than low waist you're spending more time diving than you can make up in the thrust from pushing off the bottom. And if it's getting deep quickly you may even find that you dive down and it's suddenly a foot deeper and when you go to push off your way under water. Hopefully someone hasn't started swimming over the top of you at this point, because yowch!
Watch the video again, it looks like all the people practicing dolphin dives are in chest deep water. It also looks to me that those people (who might very well just be novice, I don't really know) are coming to almost a full stop at the start of every dive. I'll plead ignorance, but I'm not sold they are moving any faster than if they just settled into a swim. And I'd also wager they are expending a lot of doing the dives since it looks like it includes (for them) a jump when already standing to create the right arc. What I would expect is something that looks a lot more fluid, where you see someone pop out of the water already in forward motion and then diving back in without any stopping or hopping.
Side note: I'd love to see what she looks like from above the water.
She is a very fast swimmer, and it's possible I'm WAY off base and she looks the same as those other people, but I'm betting her dives look a lot more fluid. I think that's her going into the water with the waves, but the waves sort of muddy the view a little. And it may very well be much harder to be fluid when your battling waves like that. I'd definitely dolphin through waves.
Enter The Dolphin
Clearly I'm skeptical, I had literally never run into a reason to use one. I've never (that I know of) been passed by anyone diving past me at the start or end of a race. I have however swum by many people in an upright position at both ends. Perhaps they were diving, I don't know, I think they mostly are walking. The swim is likely the least popular leg of a triathlon :)
So how, you ask, did I find myself diving? The answer is that I found myself in exactly the same position she talks about as the perfect conditions. I dove in, and my hands came in contact with the sand, so I did exactly what you see in the video. Pushed off the bottom with my hands (more forward than up,) got my feet under me, and launched myself into another dive. I expect that. unlike what you see in the video of the people doing it in open water. what it looked like from shore was I went under, and then came up very quickly a few feet later in an arc that immediately resulted in me being under water again. It was definitely faster than swimming, it was a pretty good feeling. I did two dives, the first from running, the second immediately after that and then I was in deep water and just swam.
Probably, like most things, the dolphin dive, when execute correctly, is a great tool. But, I'd bet that many people have almost no need for them unless you find yourself swimming through waist deep water for more than a few feet.
My guess is most of the time you're entering the water is getting deep enough fast enough that one dive (the first one) results in you getting to deep enough water that going all the way to the bottom and back up again is slower than just starting to swim. And when you're coming out (and I've mentioned this before) unless your hand is grazing the bottom or you know it's shallow for a bunch of yards, you'll spend more time looking for that perfect place than if you just swam on in.
So, if you're ever doing the Chisago race, I do think that run in is long enough to pull off a dolphin dive or two, and yes if you do it right it will benefit you. Plus it's kinda fun.