Pulling every conductor and labelling both ends.

§ 01 · What a rewire actually is

A rewire is not a "service upgrade." It is the deliberate, sequential replacement of every conductor on the boat. The breakers can stay, the panels can stay, sometimes the gauges stay; but every wire that runs between them is removed and replaced. The reason this is the right answer at all is that vibration, salt, fuel vapor, moisture, and mechanical damage age conductors faster than they age fittings. The fittings are usually fine. The wire has often been baked, cut, kinked, repaired, and re-routed for forty years.

The candidates for a rewire are typically: boats over thirty years old; boats that have had two or more electrical fires of any size; boats that have had a galvanic-corrosion event we cannot trace to the bonding system; boats whose insurance underwriter has said the word "rewire" in the survey letter; and boats that the captain knows, in the heart, are not right.

What a rewire is not: a fix for a single circuit, a fix for a chronic short, a fix for a board that was wrong from the day it was installed. Those are P-04 work. A rewire is for boats where every circuit is suspect.

§ 02 · How we work

The work is sequential, not parallel. We do not have four people pulling cable in four spaces — that is how mistakes get walked into. Two of us work in the same space at the same time, with one labeller and one puller, and we move through the boat in a documented order: bridge, then engine room, then accommodation, then deck, then hold.

Each circuit is photographed before tear-out. Every termination is photographed before it leaves. Every label that exists on the old wire is recorded. We do not assume the existing labels are correct — they often are not — but we record them so we can match them to the as-built drawings if any exist.

New conductor goes in to the labels we have written, not the labels that were there. We re-tag both ends. The size and type are stamped on the label.

We use a single brand of crimp lug per boat, marine-grade, color-coded by gauge, with the heat-shrink applied with a temperature-controlled heat gun (not a torch — ever). The heat-shrink is adhesive-lined.

§ 03 · Materials

Conductor: marine-grade tinned copper, type III stranded, to ABYC E-11 §11.6 and SAE J378.^[1] The brand we have settled on after eighteen years is Ancor Marine, both because the quality is steady and because their distribution is reliable enough that we are not waiting on three days of weather to land a wire pull.

Crimps: Ancor's marine-rated crimp lugs in tinned copper, sized to the conductor with the manufacturer's color-coded crimp tool. We do not use the Klein utility crimper for marine work; the Ancor 702010 is the right tool and we have a calibrated one on every truck.

Heat-shrink: 3M EPS-300 or equivalent, adhesive-lined, with a service temperature exceeding the worst-case engine-room temperature. We have walked into engine rooms in mid-summer that hit 140 °F at the overhead; the shrink rating is non-negotiable.

Cable management: nylon cable ties only as a temporary measure during pull. Final fixing is in stainless-steel marine clamps to ABYC E-11 §11.13. We do not leave nylon ties as the final installation method.

§ 04 · What we find behind the panel

Mostly, three things, in this order:

• Aluminum. Twelve percent of the rewires we have done since 2012 have had aluminum conductors below the waterline. Every one of those was installed by someone in the 1990s, when aluminum was briefly cheap and the trade was confused. We pull all of it.
• Cloth-jacketed conductor. About a quarter of the wood and steel hulls older than 1985 still have cloth-jacketed wire in the bilge. The cloth has often degraded to dust. The copper underneath is sometimes salvageable; we replace it anyway.
• Splices in the bilge. Always. Always splices in the bilge. Some are wrapped in friction tape. Some are inside a peanut-butter jar. Some are inside a peanut-butter jar wrapped in friction tape.

Less commonly: drum-pin terminations not stripped down to the conductor; ring lugs hand-soldered with cored solder; shore-power neutral bonded to the boat's grounding system in a way that violates ABYC E-11 §11.5.^[2] The latter is the most dangerous and the one we always look for first.

§ 05 · The deck plan

At the end of every rewire, we hand the captain a single printed sheet, drawn at a scale that fits letter or A3, that shows every panel, every breaker number, every conductor route, and the gauge of every conductor. The plan is laminated. The captain takes it home and has it copied. The shop keeps the master.

If your insurance carrier or your USCG inspector asks for an as-built drawing, this is what we hand over. We have done this a hundred and twelve times since 2008 and we have never had a surveyor reject the format.

§ 06 · Cost & lead time

A rewire is a project, not a service call. We slot rewires into the calendar four to eight weeks out, depending on the season and where the boat sits in the harbor. Lead time in the dead of winter is shorter; in October the line is long.

The rough banding for budgeting purposes is below. The single-page estimate you get from the shop will be more precise once we have walked your boat.

The numbers above are 2026 rates. Parts are billed at our cost plus 12 percent (see rates). The hourly rate breakdown is also on the rates page. The estimate is a single page and it is what you pay; if we go long we tell you the moment we know.

Cross-references: P-04 (switchboards) if the rewire is downstream of a board upgrade, P-07 (survey prep) if the rewire is what the surveyor told you to do, and the hulls log for boats we have rewired.