I'm not so sure I believe that they went to 160 ft. Without computer data or a firsthand account from the son, you just can't know for sure. It's too easy to speculate that they went down the buoy line to 130 ft as they had apparently planned, got low on air and started heading up. That would still allow for the father to go dry at 60 ft and the son to go dry at 40 ft. The son makes it to the surface, but the father does not...resulting in his body being found at 160 ft.
Based on Lifeguard quotes of what the son was saying and the consistency of the media coverage with regard to this detail, I think it's reasonable to say that the buddy pair planned a dive to a max depth of 130 fsw. The son was quoted as saying that they were down at 150 fsw. Sources within the Lifeguard/Fire & Rescue ranks, who have access to the equipment of both divers involved, state that their max depth was 161 fsw. I don't think these professionals pulled "161" out of thin air. I agree, though, that it would be nice for them to report that the dive profile was downloaded from one or both of their computers...or something to that effect.
Until now, I have been loathe to speculate as to what happened. I think I'm willing to stick my neck out on this one...since doing so may move the discussion forward. I, too, agree that going through "what-ifs" might help us be more prepared in the future.
Here is what I think may have happened:
If they did descend on the buoyline that is located at 120 fsw, I speculate that they strayed from the line, recognized they were short on air, initiated a blue water ascent, and then began to share air once the father ran out of air completely. Being inexperienced divers with limited air-sharing practice, it's likely that each diver wasn't managing his buoyancy independently. By "managing," I mean aiming for independently near-neutral buoyancy. During ascent, it's possible that the son felt "heavy" and added air to his BCD. At the same time, it's also possible that the father was dumping air...perhaps too quickly to remain neutrally buoyant. Together they may have been ascending at a safe rate. At some point, the two became separated. It's not surprising that once they let go of each other, one went up to the surface (narrowly escaping AGE or lung overexpansion injury) and the other went down. With no air left in his tank to inflate his BCD, the father's only option would have been to orally inflate it...which would have been dependent upon the amount of air he had left in his lungs. With additional wetsuit compression as his depth increased, his buoyancy would have become increasingly negative. It is entirely possible that he was overweighted to begin with and, for some reason (possibly narcosis and/or panic), he was unable/or did not think to ditch his weights.
Again, I hope that the son and family do not view this "what-if" scenario as a finger-pointing session. That's not my intention at all. Both divers were very inexperienced. Neither intended for the dive to turn out the way it did. Once they recognized they were in trouble, I have no doubt that they fought with every ounce of their being to survive. They cooperated to share air and to see each other through the incident. Unfortunately, too many factors were stacked up against them. The son is very fortunate to be alive. I hope that the Lifeguards and investigating authorities will release more facts surrounding the incident as they become available. I also hope that, at some point, the son will share his account of the incident with the diving community.
