The instructor was doing an OW dive; the pool-like conditions do not apply.
1. He did not do a pool/pool like experience at all--he went straight to open water. The students did not get the required shallow water instruction.
2. He had two boy scouts, which meant he had to have another adult. With the visibility, he should have either done two dives with you scout in each or brought in another instructor.
3. He did not do a weight check, and all three were grossly overweighted, nearly in the ballpark of Linnea. People on previous dives with him said his idea of a weight check was to slap a ton of weight on you and then see if you sunk. If you sunk, you were good to go.
4. The student's BCD was leaking. With the amount of weight he had, it needed to be full.
5. They were in shallow open water with BCDs full of air, so their buoyancy changed dramatically with any change in depth and buoyancy control for people who had no training in it was a challenge.
6. The adult on the dive lost buoyancy control and went to the surface. The instructor went up after him leaving the boys below. You simply cannot leave divers below. There was no reason to get to the surface quickly. He should have brought the boys up with him.
7. When he went back down, one boy was gone.
The testimony of the other Boy Scout differs from what you said.
From the deposition of the other Boy Scout, at page 28:
5 Q Okay. Uh, and then at some point near of the
6 surface, David stopped, and you continued, and you made it to
7 the surface, correct?
8 A Yes.
9 Q Uh, and so tell me about that. You said that --
10 your testimony is that David was floating just below the
11 surface, maybe one foot below the surface?
12 A Yes.
13 Q Within arm's length, correct?
14 A Yes, it was within arm's length.
15 Q And -- and how long did that -- so he -- was he
16 neutrally buoyant, so that he was not going down and not going
17 up for a period of time?
18 A That's -- that's what it looked like.
The deposition transcript is Court Document No. 245-11.
The point remains that it’s very difficult to follow standards 3:1 in a choppy lake with poor visibility.