Sea-Dog 8/2 AWG Tinned Duplex Marine Wire, 100 ft Black/Red

When you're running a new circuit on a boat, the wire is not the place to cut corners. This Sea-Dog 8/2 AWG duplex is flat, two-conductor marine cable built for exactly that kind of work. You get 100 feet of tinned copper on the roll, one red conductor and one black, both wrapped in PVC and bonded into a single flat jacket. It's UL and ABYC certified, so it meets the standards a surveyor or insurance inspector actually looks for.

Eight gauge is a workhorse size. It's what you reach for on higher-draw DC circuits where smaller wire would sag under load. Think windlass feeds, bow thruster runs, high-output accessory panels, and inverter DC input on a cruiser or trawler. The two conductors are already paired in one flat encasement, so a positive and negative run stay together as you pull them through the boat. That saves you time and keeps the run tidy behind the panel.

The tinned copper is the part that matters most out here. Bare copper corrodes fast in a salt-air bilge, and once the strands start to green, resistance climbs and connections get hot. Every strand in this cable is tinned, so it shrugs off moisture and stays bright for years. That's the whole reason marine wire costs more than the stuff at the hardware store, and it's why we won't sell untinned wire for a boat.

One thing worth understanding about wire gauge on a boat is voltage drop. The longer the run and the higher the current, the more voltage you lose along the way, and on a 12-volt system even a small drop hurts performance. Going up to 8 gauge on a long, high-draw run keeps that loss in check so your windlass pulls with full power and your inverter sees the voltage it expects. If you're not sure whether 8 gauge is right for your run, measure the distance from the battery and back, know your load in amps, and check it against an ABYC voltage-drop table before you commit. We're happy to talk it through if you call.

Flat duplex has a real advantage when space is tight. The low profile slides through a packed lazarette or under a gunwale easier than round cable, and it lies flat against a bulkhead so you can loom it cleanly. One habit worth keeping: cut your runs to length early rather than storing the leftover coiled up. Tinned wire that sits coiled for years can work-harden, and you'd rather have straight wire ready for the next job.

A few install notes from the dock. Use adhesive-lined heat-shrink terminals on every connection, especially near an outboard or anywhere the hull sees vibration. Plain crimps back out over time and that's where most wiring gremlins start. Where the cable crosses a sharp fiberglass edge in a bilge or locker, add a length of split loom so the jacket doesn't chafe through. And if this run is feeding an inverter or windlass, size your fuse or breaker to the circuit and put the protection close to the battery, the way ABYC lays it out. The red and black conductors make polarity obvious, but if the run sees direct sun, cover it in conduit so the colors don't fade.

Who's this for? Anybody wiring a mid-size powerboat, sailboat, or trawler who wants to do it once and do it right. A 100-foot roll covers most single-project boats with wire to spare, and having a full spool on the shelf means you're not making a parts run halfway through a Saturday install. If you're wiring a small accessory that only pulls an amp or two, this is more wire than you need. But for the heavy DC circuits that actually matter, 8 gauge tinned duplex is the honest answer.

Bottom line: this is standards-compliant marine cable from a name that's been making boat hardware for a long time. Tinned copper, flat duplex, UL and ABYC certified, 100 feet on the roll. Wire it in with good terminals and proper fusing and it'll outlast most of the gear you connect to it.