It is this part of the show that, perhaps, could have been cut down somewhat. Much of The Sea Hunters is absolutely absorbing, but the episodes I watched also contained quite a bit of filler, including apparently staged scenes showing the hunters talking about the wrecks and their respective jobs. (This isn't even counting the bonus, unused scenes featured on the DVDs.) Deep sea diving looks like fun, and I'd love to try it myself some day, but we didn't need to see several minutes of footage showing the air tanks being filled up, as in the Rusalka episode.
On the other hand, there is too much good stuff in each one-hour Sea Hunters episode to cut down to thirty minutes. At times like this, I wish North American television was more like that of Great Britain, where it isn't uncommon for shows to run for odd periods of time. Hour-long episodes of The Sea Hunters are pretty good, but 45-minute episodes would be even better.