“leds-man” is correct.

Not to be confused with an old English word spelled the same way that means one who leads the way.

My authorities for this are the OED and the American College Dictionary, but also a fellow I interviewed ten years ago who had started as a deckhand on the Mississippi in 1950, as well as a retired Mississippi pilot who piloted one of the last true steamboats operating on the Mississippi. One of them taught me over the phone to sing out the soundings correctly, which sounds a little like a hotdog vendor at a baseball game. 

There are some good glossaries of riverboat terms (“riverboat” encompasses all kinds of vessels on a river, not just steamboats) by Frederick Way, Alan Bates (2), Jack Ross, and Charles F. Lehman. Capt Lehman’s is, I think, the best, and he says “leds-man” also. These guys were all pilots and/or captains. Lehman’s lists the soundings in the order in which they are sung.

Nautical terms have odd meanings Larboard and starboard were pronounced (on the Mississippi River in the 19th century) “labbard” and “stabbard.” Leeward was and is pronounced “loowrd” (more as one syllable than two). Points and crossings can refer to a channel or to land. Ramsy and Emberson’s  A MARK TWAIN LEXICON is wonderful, but on riverboat terms I’d defer to the above fellows who actually worked on the river and produced their own lexicons.      

Kevin
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