Mahi eat almost anything that moves near the surface. Knowing what they are actually feeding on is what tells you which lure to tie on — and ten tactics for finding them once you have.
10 min read · David Rose · Species Guide
What they eat
What do mahi mahi feed on?
Mahi are not bottom feeders. They are surface-oriented predators that hunt in the top of the water column, usually within the first twenty or thirty feet, and almost always in relation to something — a weed line, a piece of debris, a colour change. If you are looking for them on the bottom, you are looking in the wrong place.
What they eat is the shortlist that decides your spread. Flying fish above everything else. Small baitfish like cigar minnows and ballyhoo. Squid. Juvenile triggerfish and filefish holding under floating grass. And smaller mahi — they are cannibalistic, which is exactly why green-and-yellow and pink-and-blue produce so consistently.
They are also voracious. A mahi can eat up to 20% of its body weight in a day, and they are opportunistic enough that on a good day presentation barely matters. On an average day it matters a great deal.
Natural baits
Ballyhoo, squid, cigar minnows. Strip baits cut from bonito bellies troll well and survive missed strikes.
Artificials
Plastic squid, swimbaits, feathered and skirted lures. Bright pinks, blues and yellows.
Skipping baits
Run closer to the boat at a higher angle so they skip — imitating the flying fish mahi prefer.
Live bait
Free-lined around debris or scattered grass. A fall-back plan that turns into a great day often enough.
The rest of this guide is ten tactics for putting those baits in front of fish.
Tactic 01
Look for surface activity
Mahi travel in large schools. Be observant for signs that might indicate fish — diving birds, flying fish or other baitfish, anything feeding at the surface. All of it is worth evaluating.
I cannot tell you the number of times I have seen something en route to a "hot spot" only to return later and catch fish around what I observed.
Birds are the longest-range tool you have for finding surface-feeding mahi.
Tactic 02
Look for debris
Large schools of mahi can be attracted to almost anything in the water. Weed lines and floating debris of any kind can hold fish. If you are trolling, troll toward whatever you see and check it out.
The size of the debris often has little to do with how many fish are around it. I recall a day we saw something floating as we headed offshore. Slowly approaching, we realised it was a 4x8 sheet of plywood. There were mahi under it almost as far as you could see. That was a great day.
Be attentive to other boats too. A good weed line attracts boats as well as mahi. Be courteous — these weed lines are often large enough to accommodate several anglers.
Tactic 03
Develop a strategy for fishing scattered grass
Finding a well-organised weed line is exciting and may lead to a great day. But often the grass is scattered, or what started as an organised weed line breaks up as sea or wind conditions change.
Trolling through scattered grass is frustrating — and the problem is that is usually where the fish are. Instead of leaving, develop a strategy for it. Because there is more ground to cover, trolling may still be the best way to locate fish, but reduce the number of lines you are running and minimise time spent clearing grass.
Another option is a weedless trolling rig. A final tactic is to stop trolling and drift among the scattered weeds — bucktail jigs, soft swimbaits and surface poppers are all good choices, and mahi will usually be there if you are patient.
Tactic 04
Consider live bait
For a variety of reasons I rarely take live bait offshore. It is most often my fall-back plan. That does not mean it is ineffective — it can make for a great day.
Use sabiki rigs to jig for live bait around bottom structure on the way out. Then free-line those baits around floating debris or scattered grass on a live bait rig to attract curious dorado.
Tactic 05
Select the right gear
If mahi are on the agenda, select gear to match. Too often we reach for tackle that will catch anything in the ocean, and that mindset can diminish the experience and even impede catching mahi.
Go lighter. 30 lb test is plenty when targeting mahi. A braided mainline with a 100-yard monofilament top-shot is a good choice, joined with an FG knot. A medium duty spinning reel and rod makes a great mahi combination — the versatility lets you switch from trolling to casting to live bait as opportunities present themselves.
Make the most of your boat whatever its size. Outriggers are a big advantage on larger boats — they let baits troll in clean water and present a wider spread. Two relatively inexpensive options compensate if outriggers are not available.
Rod riggers fit standard rod holders and point the rod perpendicular to the boat. They are very effective at getting trolling baits into clean water. Most include a lanyard to secure the rod. I have never had to rely on it, but I always use it.
Rod riggers are cheaper and easier than outriggers, though they spread baits less widely.
Directional spreader bars look like a traditional spreader bar but include a directional fin that pulls the bar to port or starboard. Usually offered in 18" or 36" widths — they develop significant drag and I prefer the 18". Even those need a reel along the lines of a Shimano TLD 25.
My preferred spread is directional spreader bars in the long position on each side and rod riggers in the short position. Depending on crew, I may run a shotgun well back down the centre. Rarely more lines than that.
Mahi hunt by sight. A ballyhoo that rolls or lies on its side is not a bait to a fish that is watching it. The moulded keel weight sits in the same position on every rig, so it tracks upright every time.
There are days when how you fish for mahi will not matter. They are voracious enough that it feels like you could troll an aluminium can and get bit. Do not count on those days.
Instead, vary both how you are fishing and what you are trolling. Have natural baits in the spread — ballyhoo, squid and cigar minnows are all good options for dorado.
If you are not familiar with strip baits, you should be. Cut from the bellies of fish like bonito or even mahi, they troll well and are extremely durable. Even if you miss a strike, a strip bait will very likely keep trolling properly.
Add artificials too — plastic squid, plastic swimbaits, feathered lures and other skirted baits will catch a lot of mahi. Bright pinks, blues and yellows are the colours to reach for.
Tactic 08
Cover the water column
Vary depth as well as bait type. Too often anglers troll swimming baits within a foot or two of the surface and leave it at that.
Diving hardbaits fool a lot of mahi. And include skipping baits in the spread — a favourite mahi food is flying fish, and skipping baits mimic them. Run those closer to the boat and at a higher angle to the water so they skip.
On a slow day, pay attention to what is producing strikes. Is it the colour? The bait type? The presentation? Then replicate the variable, not the exact lure. If a blue skipping bait gets hit, add a pink skipping bait and a blue swimming bait — and find out which half of it mattered.
Pro tip
Mahi feed upward. That means a bait needs to be above them, not below — and it is why a spread that covers the top twenty feet catches more than one that sits entirely on the surface.
Tactic 09
Don't stop trolling on hookup
The last two tactics rely on mahi being a schooling fish. When you get a fish on, there is a tendency to stop the boat and clear lines. Most often that is not the best thing to do, even on a big fish.
Keep the boat moving forward. One of the most common reasons for losing a fish is slack line, and forward motion helps anglers keep it tight through the initial excitement. More importantly, mahi school — a second or third strike is very possible. Even large dolphin swim in pairs, so if you hook a nice bull there is a good chance at the cow as well.
Tactic 10
Bailing dolphin
Smaller mahi will often follow a hooked fish to the boat, sometimes a lot of them. Always be prepared for it.
Preparation means several handfuls of cut squid, chunks about the size of your thumb, and at least two spinning reels rigged with a 4/0 live bait hook and no weight.
Look for mahi trailing the hooked fish — polarised sunglasses help enormously here. Throw a handful of cut squid across the water while you bait a spinning reel with another piece. Throw the hooked squid in among the chum and let it drift downward. If you do not get hooked up, cast again, adding more cut squid as needed to hold the school.
Once a second mahi is hooked, reel in the first. Always leave a hooked mahi in the water and the school is likely to stay. That is how you turn one fish into a boxful, and it is the most fun you can have offshore.
Why rigging speed matters
Bailing is the one situation where how fast you can re-rig decides how many fish come aboard. Every minute spent pin-rigging is a minute the school is drifting away from the boat.
Wrapping up
Conclusion
Troll to find mahi and cover as much ground as you can. Be observant for anything in the water — fish, birds, debris, grass. Troll toward it and check it out. Expect mahi to be together, and use those opportunities to catch multiple fish.
And match what you are throwing to what they are already eating. Flying fish, small baitfish, squid, and their own kind — that shortlist is why green-and-yellow and pink-and-blue keep producing, and why a bait that swims naturally will always out-fish one that does not.
Bottom line
Mahi are surface predators, not bottom feeders. Find the structure, match the bait to what they are eating, and keep the boat moving when you hook up. Tight lines and good fishing.
Your offshore partner
Match the bait. Swim it true.
TrollTrue lures hold a natural bait upright and tracking, in the colours that produce on dolphin — and rig fast enough to keep up when the school is on the boat.
Match what they eat
Flying fish, cigar minnows, ballyhoo, squid — and smaller mahi.
Cover the top
Skipping baits, swimming baits and a diver. Mahi feed upward.
Re-rig fast
Two steps, on the water, so a bailing school does not get away.
