Is anybody out here?

I'm impressed by the sparsety of shipping out here in the middle of the Pacific Ocean. Sailors talk about how inadvisable it would be to solo across an ocean. If this trip is any indication, I can see why those that do it are comfortable with it, even if they do have to leave the helm and sleep periodically.

In the three weeks we've been on this ocean we've encountered two vessels that were close enough to be seen. Both were roughly three miles away. If the crew of each vessel was asleep, what are the chances of collision? If we divide up an area with a 3 mile radius by the size of a 500' ship we have 3,100 places for that ship to be and doing the same, find 575,000 places for Quijote to be. If 26 of Quijote's spaces correspond to each of the ship's spaces we have a one in 22,000 chance of collision for each ship encountered within 3 miles. We've encountered two, so rounding off we'd have a very rough chance of one in ten thousand that we'd be run over by a ship if we crossed the Pacific solo and slept the whole way. I guess to be random the ship's captain would have to be asleep as well.

In fact Quijote, most recreational offshore vessels, and all commercial shipping broadcast AIS signals that raise the alarm when collision is likely. The chances of collision off-shore are much lower than our random geographical exercise would indicate. Not that I intend to do any solo offshore passages any time soon.