If the pilot is not satisfied, he sounds the place again; if he finds better water higher up or lower down, he removes the buoy to that place.

Being finally satisfied, he gives the order, and all the men stand their oars straight up in the air, in line; a blast from the boat's whistle indicates that the signal has been seen; then the men 'give way' on their oars and lay the yawl alongside the buoy; the steamer comes creeping carefully down, is pointed straight at the buoy, husbands her power for the coming struggle, and presently, at the critical moment, turns on all her steam and goes grinding and wallowing over the buoy and the sand, and gains the deep water beyond.

Or maybe she doesn't; maybe she 'strikes and swings.' Then she has to while away several hours (or days) sparring herself off.
Sometimes a buoy is not laid at all, but the yawl goes ahead, hunting the best water, and the steamer follows along in its wake.

Often there is a deal of fun and excitement about sounding, especially if it is a glorious summer day, or a blustering night.

But in winter the cold and the peril take most of the fun out of it.
A buoy is nothing but a board four or five feet long, with one end turned up; it is a reversed school-house bench, with one of the supports left and the other removed.