Grew up in Hawaii. While growing up, it was a regular occurrence to lay a long net perpendicular to the shore and leave it all night to catch whatever fish swam into the net (called lay net). In the morning, you'd swim out to the net and pull it in with all the fish and net and weights. This part is usually pretty cold and the gear can get pretty heavy.
I moved to the Continental US and lived there for 10 years, and got out of shape and not in the best lay net shape. Well, I move back to Hawaii for Law School and a month after moving, my Brother calls me and invites me to lay and pull in a net in a place called Waimanalo (it's generally illegal now to leave a net longer than four hours in the water, but the guys we were helping was the care taker of this particular beach park).
So early in the morning, like 5:30 am, sun not even up, about 8 of us jump in the cold morning waves and set out to grab this net, which is about 100 yards off shore and continues another 400 yards out to sea.
I am completely out of shape and within minutes, my chest is tightening and I can't breath. My lack of oxygen intake is causing my legs to hurt and cramp. I'm about 200 yards from the shore in about 20-25 feet of water. I instantly make a decision to bail.
I head back into shore. For a few minutes I really didn't think I was going to make it. I was exhausted and the cold water was sapping all of my strength and will to live. There came a point where I contemplated giving up rather than fighting on.
After thinking of my wife, I decided to try to make it to the beach. I tried to relax, but the waves were too big, I couldn't just float on my back and backstroke to the beach. When I thought I had reached the end of my strength, the one fin I had on (shared the other fin with my brother) touched sand. I tipped toed until I could walk. I pulled my self onto a bank of sand and collapsed for about an hour. I woke up to my brother and his friends pulling the huge pile of net past me on a rubber inner tube up the beach. I had the HUGEST headache.
Anyway, it was the first time I've faced my own mortality and the limits of my out of shape abilities...