I hear people say when someone fails at something they got "Deep 6'd". I assume it has to be some nautical term about getting sunk. Anyone have any idea?

I've always assumed that it meant ..buried. The depth of a typical grave is..6 feet. But as you said, it could be a nautical term and refer to six fathoms...36 feet.

I believe it comes from the sounding rope that sailors used to find water depth. When they got close to shore, or to a shoal of some kind, they would toss out a rope with a weighted end. The rope would have various pieces of cloth or such tied to it to mark the depths. One of those marks was termed Deep Six. If somebody was buried at sea they might be thought of as being in the Deep Six.

Another similar term was Mark Twain, that Samuel Clemens chose as his nom de plume.

Here is an other vote for natuical measurement

http://www.phrases.org.uk/bulletin_board/8/messages/1312.html


here is a quote from another web site


"While "six feet under" meaning "dead and buried" (from the standard grave depth of six feet) might seem the source of "deep six," it actually began as a nautical term. In the days before sonar, soundings of the water's depth were taken by the "leadman" with a weighted line marked in fathoms (a unit equaling six feet). A leadman's cry of "six deep" or "by the deep six" meant six fathoms (36 feet), or quite a bit of water, beneath the keel. Since something jettisoned into six fathoms of water was unlikely to ever be seen again, by the early 20th century "deep six" had come to mean "to get rid of" something, especially by putting it where it could never be found."