It happened in a boatyard in Freeport Wednesday afternoon.
Some 200 firefighters battled the flames.
Two workers at Approved Marine, where the boats were dry docked, were working on one of the boats when the fire started.
The men were removing a fuel tank and sparked the fire with a power saw. The fire has been deemed accidental.
The workers were taken to Nassau University Medical Center. One of the mechanics is in critical but stable condition. The other is in stable condition. Both are expected to survive but the more seriously injured has burns all over his body.
In total, 20 boats were damaged, 14 with significant damage, 6 others with minor damage.
PHOTO GALLERY: Pictures of the fire
Get Eyewitness News Delivered