Exactly! As a young Rescue Swimmer, my squadron was at NAS Roosevelt Roads PR conducting training. One fine morning, me and three other swimmers were getting ready to swim from Puerto Rico to Vieques; roughly 4 miles across somewhat shallow waters, 15-30 feet. One of our officers heard about this and came in storming mad. Telling how stupid and impossible it was and gave was a direct order not to do it. I wonder if he found out we had already done it once the previous day or not.
Great example of not being told something wasn't possible until after it had been done...