The men were on a boat in the Great South Bay when they spotted the burning house on River Street in Lindenhurst.
They used a cell phone to record the scene as they raced to the house, even climbing a 6-foot tall wrought-iron fence to get there.
Once inside, they found an elderly woman using oxygen who was trapped on the second floor of the house.
A strong shore wind made the fire so powerful that the siding on the house next door began to melt.
It took more than 80 firefighters to get the blaze under control.
Two people were taken to the hospital with minor injuries.