Underwater encounters are divided into those which occur in fresh water and those in salt water (seas and oceans). Each division is further broken down by depth—shallow and deep water encounters.
In fresh water, shallow water encounters occur at 50 ft. or less depth (where the vision is relatively easy). In salt water, shallow water encounters occur to twice that depth, i.e., 100 ft. As a reminder, the maximum depth for shallow water encounters is shown in parentheses after the designation. The numbers of monsters encountered are those shown in MONSTER MANUAL.
When a random monster encounter is indicated, go to the appropriate portion of the table and roll percentile dice. Read down the Dice Score column until the total of the dice is found, then read right to find the creature encountered. Inappropriate encounters should be ignored and a new number generated in order to gain a reasonable result. Number of creatures encountered should be appropriate to the strength of the encountering party.
Sunken Ships: These victims of storms, ice, or hostile ships can be any type of ship. They often still bear their original merchandise and treasure and just as often have inhabitants, either new creatures moving in or remains of the original crew. On a percentile die the inhabitants are as follows: 01-20 = carries merchant treasure (see “Men, Merchant”); 11-20=no treasure; 21-60 = 2-24 lacedons from the original crew; 61-00 = other monsters (roll on main chart).
Seaweed Beds: The underwater equivalent of surface seaweed, these beds are rooted to the sea floor and are from 30-300 feet high. Vision is reduced to 10 feet in beds of seaweed, and there is a 30% chance of another encounter in the area.