Sea-Dog 16/2 AWG Flat Duplex Tinned Marine Wire, 250 ft

Sea-Dog's 16/2 flat duplex is the everyday marine wire you reach for when you're rewiring cabin lights, instruments, and small accessory circuits. You get two 16-gauge stranded conductors, one red and one black, bonded side by side in a flat PVC jacket. Tinned copper runs through both conductors, and that's the detail that matters on a boat. Bare copper corrodes and goes green the first season it sees salt air. Tinned copper keeps making a clean, low-resistance connection year after year, and folks report terminals that still look good seven years down the road.

The 250-foot spool is sized for a real job. Most people buy this when they're pulling new runs through a whole cabin, or replacing a tired factory harness that's gone brittle and unreliable. We've seen a single roll cover all the interior lighting and instrument feeds on a 30 to 40 foot boat with plenty left over for bilge pump leads and the odd accessory circuit. Flat duplex pulls nicely through tight spaces too. Run it down a stringer, through a lazarette, or behind a headliner and it lays flat instead of fighting you the way round cable does. Just don't crank a sharp bend into it during the pull, because 16-gauge flat cable can kink if you fold it hard around a corner.

Sixteen-gauge is the right size for a lot of low-draw circuits. Think LED cabin lights, nav light runs, instrument power, small pumps, and switch-panel feeds. It's stranded, not solid, so it flexes with the boat and shrugs off constant vibration without work-hardening and cracking. The PVC insulation is rated for wet marine use and stays flexible when it's cold out. And the red and black conductor coloring keeps your polarity obvious, which saves you real time and real mistakes when you're landing a dozen circuits at a panel.

This wire carries UL and ABYC certification, and that's not just a sticker on the spool. If you've ever been through an insurance survey, you know the surveyor is going to look hard at your wiring. Tinned, marine-rated cable that meets ABYC keeps you on the right side of that conversation. It's the standard for a reason. Salt, humidity, and constant vibration are brutal on wire, and marine-grade tinned copper is built to take all three.

A couple of practical notes from the bench. When you strip flat duplex for ring terminals, use sharp marine strippers and take your time. The flat jacket separates cleanly between the two conductors, but a dull blade will nick the fine strands and cost you conductor. For 16 gauge, you're generally looking at circuits protected in the 10 to 15 amp range, and you'll want to watch voltage drop on longer runs. If you're feeding LED nav lights more than about 25 feet from the panel, do the drop math before you commit, and step up a gauge if the numbers come out tight. One more thing: keep PVC-jacketed wire clear of hot engine exhaust. Near a gas inboard's exhaust riser, the jacket can soften over a few seasons, so route it away from the heat or sleeve it where it has to pass close.

If a circuit pulls more current than 16 gauge can comfortably carry, Sea-Dog makes the same tinned duplex in heavier gauges for battery, windlass, and high-draw runs. But for the bulk of a boat's lighting and instrument wiring, 16/2 is the workhorse you'll use the most. Buy the 250-foot roll once and you won't be running back to the store halfway through a rewire. It's the kind of wire you spec once for a project and then forget about, which is exactly what you want from something buried behind a headliner.