Sharks are an aggressive fish found in some of the deeper parts off the coast of The Peninsula. The below map shows where some of their possible spawns are.
https://steamuserimages-a.akamaihd.net/ugc/91015800186011025...What I did was make a raft using logs and sticks and then made a bow(stick and rope) and arrows(sticks and feathers). I then rowed over to the spawn near the yacht and waited until one popped out. Then I merely pelted it with arrows until it died. They swim fairly quickly so you may need to occasionally stop firing arrows and row the boat towards them.