Ancor 122010 20/2 AWG Duplex Marine Wire, 100 ft

Ancor's 20/2 duplex cable is flat, tinned copper marine wire built for the low-current runs scattered all over a boat. You get two 20-gauge conductors, one red and one black, bonded side by side under a flat PVC jacket. It's UL listed and ABYC compliant, which means it's exactly the wire a surveyor wants to see behind your panel instead of the hardware-store stuff that turns green in a season.

The tinned copper is the whole reason to buy marine wire in the first place. Every strand is plated with tin, so salt air and bilge moisture can't chew through the copper the way they do with bare automotive wire. That tin coating is also what keeps your connections solid years down the road. Bare copper corrodes at the cut end, creeps up under the insulation, and slowly starves the circuit. Tinned strands just don't do that. On a boat, that difference is the whole ballgame.

Where does 20/2 actually go? Think light-duty circuits. Nav light runs on a small sailboat, LED cabin and courtesy lighting, instrument feeds, panel indicators, small sensors, and trigger wires for relays. It's a signal-and-lighting gauge. Anglers wiring up a set of gunwale lights or a livewell indicator will reach for a spool of this before anything heavier. And because both conductors ride in one flat jacket, you pull one clean cable instead of fighting two loose wires through a chase.

The red-and-black color pairing follows standard DC convention, red for positive and black for the return, so anyone who opens the panel after you can read the run at a glance. That matters more than it sounds. Half of troubleshooting a boat's wiring is figuring out what the last person did. Sticking to a marked, color-coded, tinned cable keeps the whole system honest and makes the next repair faster.

Here's the honest part. Twenty gauge is light. It's not the wire for a windlass, a bilge pump, a bow thruster, or anything drawing real current. Push more than about 7 amps continuous through it and you're asking for trouble. And voltage drop adds up fast on a thin conductor over a long run, so a 40-foot round trip to a masthead light can dim things more than you'd expect. When in doubt, check an ABYC voltage-drop chart and step up a gauge. It's cheaper than chasing a flaky nav light at 2 AM offshore.

A few install notes from the field. The flat profile is great for running flush along a stringer or through a wire chase, but that same shape likes to catch on edges when you're pulling through a tight lazarette. A little cable-pulling soap goes a long way. Watch your bend radius near battery switches and busbars, because a hard 90-degree kink is where a PVC jacket tends to crack first, especially in a sun-exposed cockpit after a couple of seasons. Give it a gentle sweep instead. And when you terminate, use adhesive-lined heat shrink butt connectors sized for 22-18 gauge. A sealed, tinned connection is what makes marine wire live up to its name.

The 100-foot spool is the sweet spot for a refit or a bigger project. Most folks cut it into 15 to 20-foot working lengths for cabin lighting and instrument runs, then re-spool whatever's left and stash it somewhere dry. Don't leave a cut end sitting in a damp locker for a year. Even tinned copper does better sealed and stored properly. Buy the spool once and you'll be pulling from it for years.

Bottom line: this is honest, code-compliant marine wire from a name that earned its reputation solving exactly these problems for boaters. Use it where the current is light, terminate it right, and it'll outlast the electronics you hook it to. We're an authorized Ancor dealer, so what you get is the real thing with the full warranty behind it.