| Re: Hand Held Doppler
I bought a hand-held doppler in the early '90's and took a course of sorts with Mike Emmerman and 2 other experts (can't remember their names, but I think one was his girlfriend). One of the things they mentioned was that, to an untrained ear, using a doppler was near useless as we couldn't understand what we were hearing. They then pointed out that the 3 of them, all trained, gave 3 different interpretations of a recording of a doppler check on a diver!
I used to bring mine out on the boat and use it on willing divers before and after deep dives to see if we could hear bubbles. Having a baseline prior to diving is important, so you can see if anything has changed. To be honest, we often thought we heard bubbles before we even went diving, and although I think we might have heard post-dive changes once or twice, it would be a stretch to say we thought it was a valuable tool in decompression planning, even though we were pushing the envelope with some of our profiles.
The technology may have gotten better since then, but I would think the training necessary to understand the results remains the same. We got better results inviting a trained technician out on trips to doppler the divers. It is important to make sure the tech take some sort of seasickness preventative if you want to get anything out of him though...
John Yurga |