Lots of stuff over time. One of the more interesting ones was an 8 ft. long, five compartmented side scan sonar fish leaning against a third reef ledge. One of my Ocean Engineering professors had lost and abandoned it. I found it a few days later after only three dives guess at the location within a 1/2 mile by 1/2 mile area. It was designed to automatically tow 15 ft. off the bottom, to explosively deploy a bunch of pingers and operated at a relatively high frequency for target definition. It cost $1,000,000. originally in the early 1970's but was totally of analog technology. So, it may have been a very, large and formerly expensive paperweight. As paper money sinks, I've found lots of that. In fact there are certain areas of reef which can be relied upon to trap it. I once found a new 70 hp outboard (traded for $$$ again in the college days) along with some gold jewelry from the same abandoned shipwreck over a 1/2 mile offshore decades back. Tons of anchors, my favorite during my impoverished college days were plow anchors, usually good for a $100. at Sailorman every time. There is a great deal to be found in the sea, start looking ...