Well, it turns out Vasa trainers are no joke. And, they're so legit they're actually made in the USA. In Wiliston Vermont no less (go VT). My swim coach recommended I try it out to help improve my feel for a 'high elbow catch and pull.' Getting your elbow up and your hand down quickly while engaging your lats is the key to a strong swim stroke. It's a little harder to accomplish than it sounds on paper though. That's where Vasa comes in. You can really fine tune your sense and tolerance for the elbow 'pop-up' required to engage the lats rather than the deltoids and traps, and drive your hand down to perpendicular with your body and the pool bottom.
You've probably read that you shouldn't pull till your hand is down. Well, this turns out to be a little bit misleading. You're actually wasting good water by letting your hand drop without engaging your lats and core muscles. I'll let Brett step in here because I'm really no authority on an efficient pull, but if you're struggling with strength and balance issues, 5 minutes on a Vasa trainer pre and post swim can help you develop the muscle memory required for a strong, steady pull. Try it with a mirror in front of you. Not a glass one dummy, you're on a freaking pool deck. Just one of those cheapo ones from Dollar General. Watch your stroke then compare to video of Mikey Phelps and the rest of the elite swimming gang (can anyone else name a famous swimmer? Mark Spitz? Am I making that up????). Every fast swimmer in the world moves their hand the same way. Monkey see monkey do. Do it!
Alrighty. Now flip to page 181 of the the January issue of Triathlete Life (you know, the annual pants-stuffing-can-help-you-add-five-watts-to-your-ten-mile-TT-time issue) and order yourself up a ridiculously expensive sliding weight bench.