@PfcAJ, Most of your retorts are generalizations or ad absurdum type or arguments that work when diving in a quarry or something similar. Not advisable for ocean diving.
Consider this scenario with my local diving. I am diving at 90' on a wreck in NJ. There is some current and visibility is about 10'... not too bad for a day in the North Atlantic. I am around 300' from the down line fishing out of the current on the wreck with my teammate when I realize we are separated. I look for around 1-2 minutes and decide further searching is not advisable.
Do I now do a free ascent in low visibility 300' feet from the boat or do I travel back to the up-line and do my ascent there.
If I choose the former I could be on the surface in around 2-3 minutes but who knows where I will surface? Maybe 300' or further from the boat, not including if a current pushes me and what the seas are doing. The boat can't just pull anchor and come get me with other divers in the water. I most certainly will not locate my buddy on the surface if the seas are anything but flat calm.
I personally have seen people decide to do this and be swept 500-1000 feet from the boat quickly and requiring rescue from the Coast Guard. They inflated their SMB, they blew their whistle but to no avail.
If I choose the latter option, without a pony, I now have a travel time of 6-10 minutes with no redundancy. Maybe nothing happens but as the adage goes, Nothing Happens Til It Happens. A pony package all in is around $350.00, tank, reg and rigging. My life is worth $350.00...I just decided not to buy coffee at the office this year, I'll bring it from home.
---------- Post added October 30th, 2013 at 11:34 PM ----------
Absolutely agree here Steve. The more time I spend in my tek gear the more familiar with it I will become. After a few hundred dives now I can find things without even having to think about it...muscle memory! In an emergency it can save your life.
I have heard Dale's, "Why you wearing all that gear, we're only going 70'". My retort is always, "You worry about you and your teammate and I will worry about me and mine."
Same goes with my pony. I dive it whether I am at 40', 80' or 140' (albeit a bigger size). As we have seen from Accidents and Incidents, you drown just as easily in 15 feet as you do at 150'.