About San Diego Trough / 43 Fathom Spot

The San Diego Trough, also known as the 43 Fathom Spot, is an outer-exposed drop-off southwest of San Diego where a mixed bottom falls through roughly 180 to 300 feet of water. Rockfish hold along this structure year-round, while lingcod concentrate from October through February and ocean whitefish peak from March through October. Anglers work the rockfish with dropper loop rigs baited with squid, mackerel strips, or anchovies, and switch to vertical jigging with metal or slow pitch jigs when fish sit tight to the rocks. Lingcod respond to vertical jigging with heavy iron and swimbaits on lead heads, or a live bait dropper loop with live mackerel and sardines pinned to the drop-off edge. The depth and steep relief also bring sablefish within reach of deep dropping with squid and mackerel strips, alongside sharks that patrol the exposed water above the trough.