A Type III for F/V Cape Fox

The 32-foot Bristol Bay-class gillnetter F/V Cape Fox is one of the four working fishing vessels that winter in Port Townsend each year and make the late-May ferry run up to Naknek, Alaska, for the salmon season at the head of Bristol Bay. Her owner-operator, who has fished her since he bought her from her builder's estate in 2009, makes the run every year on the back of a Lynden Inc. transport barge out of Seattle. The boat itself spends the season working out of Naknek on a 32-foot legal-length permit, fishing the Naknek-Kvichak district for what is, in most years, the largest sockeye return in the world.

What changed in 2025, for Cape Fox and for the four other Port Townsend gillnetters, was that the State of Alaska started enforcing its long-standing marine-sanitation requirements differently. The relevant federal law has not changed since the 1972 Federal Water Pollution Control Act; what has changed is the enforcement posture of the Alaska Department of Environmental Conservation in the Bristol Bay watershed, where the salmon-spawning streams are now subject to a documented no-discharge regime that — as a practical matter for the gillnet fleet — means a working Type III MSD on every vessel fishing the district by the 2026 season.¹

Cape Fox, like most of the small gillnet boats, has been fishing with a portable bucket head for thirty-some years. Her owner needed her to come back in 2026 with a real Type III on her, properly installed, properly documented, in a way that would survive an ADEC dockside inspection in Naknek without questions. We got her in on the second week of January and went to work.

What is a Type III MSD, exactly?

For the readers who do not work this end of the trade: Type III is the simplest of the three USCG-certified marine sanitation device categories. It is, in regulatory language, "a device designed to prevent the overboard discharge of treated or untreated sewage or any waste derived from sewage."² In trade language, it is a holding tank — a tank that catches what the head sends, and that has to be emptied somewhere else. Type I is a macerating chlorinator that puts treated effluent over the side (1,000 fecal coliforms per 100 mL, no visible solids; legal outside a No Discharge Zone). Type II is a higher-treatment unit (200 coliforms per 100 mL, 150 mg/L suspended solids). Type III is the tank.

Type III is the default install for any vessel that operates inside a No Discharge Zone — and the entire Puget Sound has been an NDZ since 10 May 2018, with the Strait of Juan de Fuca added in the same rule.³ Bristol Bay is not an NDZ at the federal level, but the ADEC requirements that Cape Fox's owner now faces have the practical effect of one for the duration of the season.

The Y-valve question

The question that comes up on every Type III install on a working fishing vessel — and which we get a letter about in every other issue — is: "Do I install a Y-valve, so I can dump the tank overboard when I'm outside the three-mile limit?" The answer is: yes, but with discipline.

The USCG-required Y-valve installation for vessels with overboard-discharge capability has two parts. First, the Y-valve itself, which routes the head's output either to the holding tank or to the overboard discharge through-hull. Second, a hardened mechanism to render the overboard discharge "incapable of being used" while the vessel is in an NDZ — usually a padlocked valve handle, a removable handle, or a wire-tied closure that requires deliberate breaking. The Coast Guard inspector cares about the closure as much as the valve.⁴

On Cape Fox, we installed a Raritan three-way Y-valve at the discharge from the Raritan PHII manual head, with the overboard leg fitted with a stainless-steel padlock-and-hasp closure. The owner has the only key. We documented the closure mechanism photographically in the install report, and that documentation will go to ADEC with his 2026 vessel certification. The padlock is the cheapest insurance on the boat.

The tank

The tank itself is a 38-gallon cross-linked polyethylene (XLPE) Ronco TT-2000 series, custom-modified by Ronco Plastics of Tustin, California, with two top-mounted fittings: a 1.5" NPT discharge inlet on the forward end (which receives the head's output) and a 1.5" NPT pumpout outlet on the after end (which feeds the deck pumpout plate). The pumpout outlet is the one the Naknek dockside pumpout will hook to. The discharge inlet is the one that connects to the Y-valve. The tank carries a 1" vent up to a clamshell vent on the lazarette aft bulkhead, with a Sealand vent-line filter (which catches the sulfur smell that otherwise would drift forward).⁵

The trend in better-quality marine holding tanks — and we follow this trend — is to use top-mounted fittings exclusively. The reason is that any fitting installed in the side or the bottom of a tank creates the possibility of sewage sitting in the discharge hose during a heavy heel; bottom-of-tank fittings, in particular, are how a poorly-vented holding tank ends up depositing a corrosion-failed copper Y-valve at the back of a lazarette. Practical Sailor's 2015 holding-tank comparison made this argument first and we have followed it since.

The tank sits in the lazarette, on a Coosa-board cradle bonded to the after-deck stringers, with two 2" nylon webbing straps to a pair of stainless padeyes. We measured the lazarette on day one, sent the dimensions to Ronco on the second day, and received the tank on the eighth working day. Lead time for a custom Ronco order, for those keeping score, runs about ten working days in the off-season and 15–20 in the spring rush.

The hose

The single most consequential decision on a Type III install is the choice of sanitation hose. Practical Sailor's 2018 marine-sanitation-hose test compared eight common hoses for permeation, flexibility, and stiffness; the test ranked Trident Marine's Sani-Shield 101/102-series at the top for permeation resistance, with the trade-off of being stiffer than most.⁶ We use Trident 101 throughout, on every Type III install we do, on the rationale that the smell complaint is the single most common owner-side complaint and Trident 101 has the lowest documented permeation rate of anything currently on the market. Cape Fox got 9 linear feet of 1.5" Trident 101, all of it routed on long radii, all of it double-clamped at every fitting with all-316 stainless hose clamps.

The deck pumpout

The pumpout plate sits on the after deck, port side, just forward of the lazarette hatch — close enough to the dock when she comes in port side-to that the Naknek pumpout boat operator does not have to climb aboard. The plate is a Perko 1283-series stainless flush deck plate with a 1.5" NPT through-deck fitting, backed with a 1/2" Coosa-board reinforcement disc, bonded with 3M 5200.

The plate is labeled in 1/4" engraved white letters: WASTE — DECK PUMPOUT — KEEP CLOSED. The labeling is not a regulatory requirement, but it is the difference between a pumpout operator who finds the right plate on the first try and one who, in front of the next boat in line, gets the diesel-fill cap by mistake. We label every pumpout plate this way.

The owner's responsibility

What we install is the system. What the owner is responsible for is the operation. We hand off every Type III install with a printed binder that includes: the as-built schematic; the through-hull location diagram; the vent-line layout; the padlock key; a written record of the closure mechanism (which goes to ADEC); a list of the nearest pumpout facilities in Washington State Parks' pumpout program and in Naknek; and a one-page operations sheet on what to do when the tank reaches the high-level alarm. Cape Fox's owner has been through one Type III install before, on a previous boat in 2007, and did not need the operations sheet; we gave him one anyway, on the principle that every install gets the same paperwork.

What it cost

The full refit invoiced at $4,920 plus tax: $1,640 for the Ronco tank, the Raritan Y-valve, the Raritan PHII head, the Perko deck plate, the Sealand vent filter, and miscellaneous fittings; $620 for the Trident 101 hose, hose clamps, and the seals/sealants; and $2,660 in labor for fabrication of the cradle, installation of the tank and head, hose runs, hardware, deck-plate install, vent run, and the final pressure-and-leak test. The Port's haul-and-launch tariff was, separately invoiced, $610 (20-day yard slot, Block 14, plus launch and re-launch).

The aside

(One first-person aside per feature, from the tradesperson who led the work. — Editor.)

I want to say a word about the Bristol Bay fleet. There are roughly eighteen hundred 32-foot gillnetters fishing the Naknek-Kvichak district at the peak of the season. Most of them have been built since 1980, and most have never had a working MSD installed. The ADEC enforcement push that hit the dock in 2024 caught most of the fleet flat-footed, and the four Port Townsend boats are doing better than most because we have, between SEA Marine and our shop, the capacity to turn around a Type III install in 15 working days. The fleet boats that come in to us during the spring rush — Anacortes, Friday Harbor, sometimes Cordova — are paying premium for the season-rush slot. Cape Fox got in early because her owner started in January, not in April. The four-month lead time is what we need to do a job this size without cutting corners. The owners who call us in April get a list of three other shops we trust on the peninsula. — S.A., 2 February 2026.

Returned to the water

We launched Cape Fox at 1410 on Tuesday 3 February 2026, on the falling end of a 9.1-foot tide, into a 6-knot ebb against the Travelift pit. The Y-valve was tested at the dock with the holding-tank inlet open and the overboard padlocked closed; the head pumped to the tank for five strokes and we pulled the pumpout hose to verify flow. The vent passed a vacuum-test (5 inches of water, 90 seconds, no draw-down). The owner motored her over to the gillnet anchorage at the south end of the boat haven inner basin, where she will sit until the Lynden barge picks her up in mid-May for the Bristol Bay run.