Sea-Dog 6/2 AWG Flat Duplex Marine Cable, Tinned Copper, 100 Foot

When you're running heavy DC current across a boat, 6/2 AWG is right in the sweet spot. It's big enough to feed a windlass, an inverter, or a house bank without cooking the wire, and it's still flexible enough to pull through conduit and around bulkheads. This is Sea-Dog's take on it: two 6-gauge tinned copper conductors, one black and one red, laid side by side in a flat PVC jacket, sold on a 100-foot roll.

The word that matters most here is tinned. Every strand of copper is coated in tin before it's bundled, and that thin layer is what keeps salt air and bilge moisture from turning your conductors green. Bare copper corrodes from the cut ends inward, and once it does the resistance climbs and the connection heats up. Tinned copper shrugs that off. It's the difference between wiring you do once and wiring you're back chasing in three seasons. If you've ever cut into an old run and found black, crumbly strands, you already know why we won't sell untinned wire for a permanent install.

The flat, or duplex, shape earns its keep during the install. A round cable of this gauge wants to stand proud wherever it sits. This one lays flat against a stringer, tucks under a cabin sole, and runs along the edge of a locker without a big bulge fighting you. On boats where the wire has to disappear under carpet or trim, the flat profile is the whole point. Both conductors travel together in one jacket, so you pull one cable instead of trying to keep a positive and a negative buddied up over a long run.

Color coding is simple and it's marine-correct: black and red, so there's no guessing which conductor is which when you land it. That matters more than it sounds like it should at two in the afternoon in a hot engine room with your arm buried behind the panel.

Where does 6/2 actually go? Windlass feeds are the classic one, especially on a mid-size cruiser where the run from the battery to the bow is long and the loads are real. Inverter cabling is another, along with charger feeds and main house-bank runs on larger monohulls and trawlers. The 100-foot length is sized for those longer hauls, bow to helm or battery to inverter, with enough left over that you're not splicing mid-run to make it reach. On a smaller boat you'll have plenty to spare, and honestly that's fine, extra length in the bag beats coming up short.

A few install notes from folks who've pulled a lot of this. When you're feeding it through a tight lazarette conduit, a wrap of tape every few feet keeps the flat profile from binding as you pull. Size your fusing to the load and the run, not to the wire, and keep an over-current device close to the battery. At every termination, use adhesive-lined heat shrink over the lug. Tinned copper resists corrosion, but a sealed, weatherproof termination is still what keeps water out of the connection over the long haul. And in an exposed bilge run, drop it in split loom, because chafe and standing water are what age any jacket fastest.

One more thing that surveyors care about: this cable carries UL and ABYC certification, which is exactly what an inspector wants to see on a high-current feed. Just remember the printed rating lives along the jacket, so when you cut a length, note the certification before you trim, because a bare cut end doesn't show it. That's not a knock on the wire, it's just how marked cable works.

So who's this for? Anyone wiring a windlass, an inverter, a charger, or a house bank and doing it once, to standard, with wire that'll still be solid when you sell the boat. It's not the cable for a nav light or a bilge pump, that's lighter-gauge territory. But for the heavy DC runs that carry real amps, 6/2 tinned duplex is the honest answer, and this roll gives you a full 100 feet to work with.