| A striped marlin often shows both the upper portion of its dorsal fin and the tip of its caudal fin when the fish is tailing or feeding, but the dorsal fin is usually angled steeply back, or folded completely, when the fish is "sleeping."  As the sunfish, or mola mola swims at low speed, the semi-flaccid tip can droop and flap slightly from side to side.  The dolphin or porpoise exposes most of its dorsal fin above water as it slowly curves its body above the surface. The dorsal usually shows more curvature than those of sharks or marlin.  manta rays often cruise slowly on the surface. Sometimes, in this mode, mantas will curl and raise a smooth, rounded wingtip above the surface.  Most sharks have a softer, more rounded lobe-tip at the top of their dorsal fin, with usually about one-third of it exposed.  A seal or sea lion often rests or suns itself by lying on one side and floating, displaying one of its pectoral flippers for view, often waving it in the air.  A broadbill swordfish on the surface will expose half to three-quarters of a pointed dorsal fin with a scythe-like curve and broad base.
Illustrations: Steve Sanford
If there was a Pacific Marlin Fishing Hall of Fame, its corridors would surely echo the names of Pete Grosbeck, Gary Graham, Gary Jasper and Mark Wisch. Over the years I've enjoyed fishing with, interviewing or attending seminars conducted by these tournament pros and others men who have mastered everything from reading current breaks to understanding the roles of prop noise and stern turbulence on marlin behavior. Here's what I've learned from these experts and others on one vital aspect of striped marlin angling hunting and baiting fish on the surface.
DON'T BE FOOLED BY FINS
Learn to recognize the surface-protruding shapes and characteristics of fins of various sea creatures. There are subtle, yet very important differences (see illustration).
A marlin, for instance, will often have portions of both its dorsal fin and tail fin showing; not so with most other finners. Know that the pectoral or side flipper of a sunning seal slowly flaps up and down, while the broad, dorsal tip of a lazing sunfish (mola mola) appears droopy. A shark's more rounded dorsal is usually only about one-third exposed, except when aggressively feeding; the dorsal of a swordfish is scythe-shaped and pointy, compared to a marlin's.
If you can't distinguish the fins of a stripie from a sunfish or a shark, you're going to waste a lot of time, effort and fuel investigating non-targets.
BE A BIRDWATCHER
|Greyhounding striped marlin provide a thrilling fight.
Sea birds are some of the world's best anglers; they have to be to survive. These hunters pursue the smaller forage fish that large predators, such as marlin, herd and drive to the surface. Even at some distance, birds can tip you off to the presence of marlin.
But not all birds are created equal as anglers seagulls and pelicans, for instance, don't offer the same target-acquisition reliability as do terns, jaegers or petrels.
Birds on the hunt fly in a fairly straight line and with evenly measured, yet rapid, wingbeats. Watch carefully: These clues reflect how the birds track and react to the swimming direction of a marlin.
Birds holding above feeding billfish will hover while selecting their own targets, then tuck in their wings, extend their necks and dive-bomb into the sea. There's very little chance of mistaking a "bird school" as they're called by anglers when a flock of terns, frigates, jaegers or petrels is frantically circling, dipping, nose-diving, then piercing the surface, feasting on the forage fish.
THE BEHAVIORAL APPROACH
Just as learning bird behavior makes a better marlin angler, so does understanding the actions of surface-oriented stripies. When spotted, a marlin almost always exhibits one of four modes of behavior: jumping, sleeping, tailing or feeding.
Still, on slow fishing days with little or no other surface activity, chasing an occasional jumper may produce that infrequent hookup.
On otherwise great fishing days, you can pretty well write off jumpers as they're not worth the effort.
When a feeding frenzy erupts near your boat or you slide up on feeders that you've approached from some distance you've found nirvana. And in the excitement, the angler's toughest challenge may simply be to retain composure and not backlash on the cast.
TAKE A BOW
To get a bait to a surface-oriented stripie, many anglers prefer casting from the bow. And since many marlin-outfitted sportfishers feature bow pulpits, these elevated casting platforms make the underhand lob cast easy to master.
The height above water of many pulpits allows an angler to dangle his bait and lob-cast it via a longer leader, generally at least the length of the rod itself (around seven to 71/2 feet, compared to the longer leader length used on a dropback-bait outfit in the stern). If possible, the skipper should approach the marlin from downswell, then slow the boat at such a distance that the boat's slide takes the angler into casting range.
A well-placed lob cast aims for a spot six to ten feet ahead of and beyond the fish. A bait splashing down at that point will turn the marlin's head and its attention away from the boat. Conversely, a bait cast between the fish and boat may spook or disturb the fish, or switch the marlin's focus to the hull, not the bait.
Anyone serious about catching striped marlin should become an accomplished bow caster. It's simply a prerequisite to consistent billfishing success. At marlin tournaments, I've seen top-notch angling teams compete in land-based mackerel-casting contests, during which contestants stand on an elevated platform and lob a weighted, vinyl "fish" into a filled wading pool. Even at a distance of 50 to 75 feet, it's remarkable how many pro casters are dead on target inside a 72-inch-diameter ring.
TAKE YOUR BAIT OUT FOR A WALK
If a stripie doesn't strike a bow-lobbed bait the presentation isn't over yet. As the boat continues to slow and slide, the angler walks his bait along the side of the boat while still free-spooling line, continuing the walk until stepping down into the cockpit. Then a thumb on the spool holds the line in place while the bait is towed, then soaked, 80 to 100 feet beyond the still-slowing boat.
A second angler is ready to reel in the trolling lines if a marlin takes the live bait. Often, a bow-baited marlin refuses the first offering, but reappears astern and takes a bait that has been walked into that position.