/From 1863/ 



FIG. 1. Distribution of Sea Snakes in the South China Sea 

 and East Indian Ocean From November 1963 through March 

 1964 (For the Gulf of Tonkin, the data pertain to 1961). 



1 - Snakes have not been noticed; 2 - 1 to 5 snakes; 

 3 - 5 to 10 snakes; 4 - 10 to 25 snakes per 1 hour with the 

 speed of vessel being 10 knots. 



