Seems like Swellinfo ongoing forecast issue is lingering. Looked around for alternative, found stormsurf.com.
Graphics are last decade, but the surf forecast and weather information is extensive. Mark Sponsier created the site back in 1998. He packed the site with information on how waves are created, tracked and forecasted.
The 5 day forecast for Gilgo is part of a broader New Jersey to New York forecast, but serves up some good info.
There is also a buoy forecast looking out 5 days that has couple of different reporting screens, here is Buoy 440025, 30 miles south of Islip.
Check out their Tutorial Page for some in depth explanations. Last, one odd situation is that the site is not https, site is still running in the clear.