For optimal scrap gathering you'll want to focus on diving near island reefs, since they consistently spawn 20+ pieces around rocky formations. Watch for the shark's fin pattern - it circles clockwise before attacking, giving you about 8 seconds between passes. Drop shark bait roughly 15 meters from your target area, as this keeps the shark occupied for exactly 45 seconds giving plenty of looting time. When approaching coral clusters, position yourself directly above before descending, this gives maximum oxygen efficiency while gathering.

Keep your nets aligned at 45-degree angles during island transitions, and check them every 3-4 minutes since barrels spawn in predictable intervals. The shallow zones around island perimeters typically contain 4-6 scrap deposits within a 20-meter radius of the anchor point, though deeper spots near cliff edges can hide additional clusters. Remember that the shark's attack animation has a 2-second windup where its fins glow slightly - that's your signal to move. Recyclers process items every 30 seconds but don't generate scrap directly, so focus on reef diving until you've established proper trade routes in the later phases.

A neat timing trick: if you position yourself between two close scrap pieces, you can chain-collect them with the hook's 1.5-second recovery animation, maximizing efficiency between shark cycles.