The past weekend I got a wild hair and drove 200 miles south of Dallas to a beautiful lake in Austin, Tx. Lake Travis is really pretty and deep at a depth of 170'. It was a beautiful sunny day with air temps in the 80's. Surface temps of water were in the low 60's and temp at depth was upper 50's. The lake has the perfect setup for freediving with a small platform anchored with a chain just 80 yards off shore right near the dam. After about a dozen warmup dives to some of the sunken boats, I started pulling myself up and down the chain from the platform. I started with a 30' dive and added about 10' with each additional dive. I had a little trouble clearing my ears at 60' but felt comfortable with each depth. On the way down to 75' I had to stop twice to clear my left ear which was clearing very slowing verses my right ear which cleared instantly. I hung at 75' for about 5 seconds and started heading up. It must have taken me longer to get down that I realized because on the way up I began to feel the strain to breathe. When I broke the surface I grabbed the platform and took a few deep breathes and felt fine. Within 6 seconds after surfacing both my hands gave a single quick twitch which seemed to be involuntary. Nothing too dramactic, just that my fingers seemed to clamp closed for just in instant. I felt completely lucid and was trying to figure out whether or not if I had purposely squeezed my hands closed due to the cold or unconsiously. Your thoughts?