My husband and I decided to get a boat to avoid the charter game, and for several years we did just that... throw the anchor, yes with a lot of scope, with plenty of chain.
We went down the line and made sure the anchor was truly set, if viz wasn't great we use one of our reels from the anchor to guarantee that we would find the way back.
We did this shallow and deep, off Panama City Beach and off the Pompano area, never an issue. Until one day.
That weird day during a shallow dive on Pompano, great viz, calms seas, nothing out of the ordinary. A location we had done so many times I think the garden eels recognized us when we showed up. On the way back at the end of the dive immediately we spotted the anchor but wait something is not right... the chain is laying down as it should but so is about 10 or 15 feet of line just laying in the sand, keep looking expecting to see the a cut off line or something, but no it was the continuation of the line from flat in the sand to perfectly vertical to the surface, what?? I didn't know what to think neither did my husband but we started to move fast to it. Before reaching the line the whole assembly: line, chain and anchor took off, at that point we both figure someone was stealing the boat, my husband managed to grab the line and work his way up to the boat.
It was a freak kind of storm, some how the wind stop to zero, which caused the line to go flat, the very strong wind started fast in a direction opposite to what it was when we first set the anchor, that turn the boat around and let the anchor loose.
the boat would've ended on some rocks, unless it crashed to another boat on its path. On that location we could've swam to the shore but that made us wonder of all the what ifs.
On few occasions we have left the boat after that, but not often and mostly keeping an eye on the line.
We decided that is better to dive solo one at a time than together leaving the boat empty.