I'd just about believe the photo date--the combination of diamond stack and enormous headlight (product of the need to collect and concentrate as much of the light from a kerosene lamp as you could) suggest it was built in the 1870s or 1880s, and would easily be still in service in the '90s.

None of the crazily strung electricity or telephone poles which are ubiquitous in many Shorpy photographs. As for water, no sign of an incoming pipe. That looks like a water tower for the locomotives by the side of the railway track. Could have been useful for the house too. I suppose we don't have to think to hard about how outgoing water, etc was handled.

Living over the water is one thing, but doing so in a bustling harbor leads me to think this was probably the home of someone like a harbormaster or customs official, and came with the job. No commuting necessary!

As Rute Boye suggested below, then my money is on a hurricane.

A house out over the water, now we have a steam locomotive out front, what's next?

I like beaches and water too, but I don't think I'd build such a spacious home on such an "iffy" foundation. Perhaps the man on the front porch was anti-social or just liked to be left the heck alone with his thoughts.

This appears to be another angle to an earlier Shorpy image.

but I predict that sooner or later it burned down.