Judging from the position of all the flags, as well as the idle sail of the boat, the wind was moving from left to right. So, the smoke or steam likely came from the far (left) side of the dock.

The machine at the left edge of the photo could be some sort of pile driver, though I could find nothing resembling it on the web. The poles and lumber lying on the pier may have been part of a maintenance effort. If this machine was steam-driven, then it's possible it was the source of the smoke.

[That's a ferry landing; the "pile drivers" are counterweights for ramp. - Dave]

What do you think is causing the big cloud of smoke at the shore end of the pier? It looks like it is coming from underneath the water. When did this pier (as everything else of the era) burn down?

Brooklyn Life (Brooklyn, New York) 30 Oct 1915, Sat • Page 25

Not very often these days do we see a vessel (in this case a gaff-rigged catboat) left in its slip with its sails still hoisted. But, until the advent of modern synthetic fabrics, leaving sails aloft for awhile was commonly practiced in order to dry the heavy cotton canvas from which they were made. Moisture-induced mildew, rot, and rust were a constant plague in the days of wooden ships and iron men.

What is the steam or sea spray at the bottom left third? The water looks fairly calm, so I'm presuming it's steam, but from where?