Planing a fish is sometimes required, especially for a large shark, swordfish, marlin or tuna holding near a thermocline deep in the water column. As a last-ditch resort, slowly creep the boat forward as line leaves the reel. Try this in 200- to 400-foot increments, then slowly back down on the fish while applying heavy pressure to reclaim line. Sometimes this moves a fish to higher levels within the water column and eventually to the surface.
I employed this tactic five years back to plane a big swordfish to the surface for Carl Grassi, after a fight that spanned six hours and over 26 miles of ocean. Grassi battled his fish on 80-pound stand-up gear, only to enter a stalemate near the end. The fish couldn’t be budged, despite our tricks. We attempted to plane it, as outlined above. The gains in line were painfully marginal, but we were gaining. Some 30 minutes into the planing routine, a huge sword popped to the surface. We fly-gaffed and boated the fish. It weighed 380 pounds on the scale at Bud n’ Mary’s Marina in Islamorada, Florida. The planing move paid dividends for us that day.