Eskilady,

It's doable, but that good weather could make it more difficult.

I calculate it to be about 490 miles driving distance and about 10 1/2 hours on paper. Unfortunately, driving in the vicinity of NYC can change the paper so to speak.

I'm assuming you'd be leaving close to the area the cruise is going directly to Montauk then backtracking to Fire Island and then straight to Syracuse.

You'd benefit somewhat from already being on the Island , stating early and then be going in the opposite direction of the traffic. This assumes a very early start.

You'd have to add about 3/4 hour walking time from the parking lot to Fire Island Lighthouse (R/T).

It's about 90 miles out to Montauk from Hicksville (just used this as a starting point) and about 2 1/2 hours and then about 100 miles from montauk to Fire Island and about 2 1/2 hours. Then the trip to Syracuse would be about 300 miles and about 5 1/2 hours. I'd add about 1 1/2 hours to this driving time and add 3 hours for walking to and walking around the Lighthouses and your talking 15 hours or so.

As I said it's doable, but it's a long day.

Dennis