I once had an interesting pool experience...
Several years ago...
boulderjohn,
There is very little chance, I think, of these types of things happening in the "long, thorough course" I'm referring to in my post #10 in this thread.
For example, my course, which employed harassment at progressively more liberal levels, began with a lot of physical conditioning and swimming and skin diving training. In fact, our earliest pool skills involved *only* a mask and snorkel (and weight belt): Buddies face each other, *standing* in the bottom of the shallow end of the pool, with one hand holding onto the side of the pool. They begin breathing off of their snorkels and, slowly kneeling, submerge first their mouthes, then their eyes, then their entire heads. Under their TA's direction, one at a time each removes his/her snorkel from his mouth (so it floods; careful: diver must be bubbling when something isn't in his mouth!) and then replaces and purges his snorkel and continues breathing. They do this for several repetitions before they stand up.
They remove their masks, and repeat what was just done with their masks on.
Then they replace their masks and discard one of the snorkels. And then do a variation of this skill, but buddy breathing off of the one remaining snorkel (careful: the diver who "owns" the snorkel must "control" it)
Repeat with masks off.
This first skin diving two-hour pool session ends with the divers hurling their masks (with snorkel) down the shallow lanes, then swimming (alternately surface swimming and underwater swimming) to dive down to the mask and, remaining underwater, retrieve it, put it on, clear it, and purge the snorkel, before standing to repeat.
(Actually, the pool session ends after the divers have washed and put away their gear and swum their required increasing number of laps.)
BTW, before the buddy pair commenced their skill, the skill was demonstrated by a pair of TA's.
Oh, I left off the part where the TA gradually scoops water into the diver's snorkel while he is breathing off of it so that the diver experiences what it feels like to breathe off of a "wet snorkel" as he might have to in rough seas. (BTW, the students are invariably surprised and delighted by just how much water can be tolerated in a snorkel, how much water one can "breathe around.")
Imagine: a two-hour wet session devoted to only these elementary but essential skin-diving skills!
Okay, many people will likely conclude that a (necessarily) long, thorough scuba course that progresses this way will produce students who are less likely to panic, less likely to reach their panic threshold. Harassment skills, appropriately introduced, are entirely appropriate, imho, for such a long, thorough course.
Safe Diving,
rx7diver