limitations, the unique history of SQUAW and the scarcity 

 of similar data justify recording of the findings. 



HULL FOULING 



Fouling on the SQUAW exhibited a striking vertical 

 zonation (fig. 1), and each zone contained a distinct assem- 

 blage of organisms. For the purpose of this report the 

 zones will be designated as follows: 



1. The upper zone: The top deck and sides down to 

 a heavy mat of Ul va sp. (a green alga commonly known as 

 sea lettuce). This region was exposed to sun and air for 

 over 30 days after recovery. 



2. The uiva zone: The heavy mat of Ulva on the 

 upper sides of the pressure hull. 



3. The free zone: The 2 -to -3-foot strip around the 

 hull, just below the Ulva zone, which was free of major 

 fouling. 



4. The lower zone: The bottom and sides below the 

 free zone. 



