Disruptor Launched, New Custom Mussel Ridge 46

Eighteen months after contract and 12 months after the hull arrived in Newport, we delivered Disruptor, one seriously exciting 46-foot fishing machine. And she’s already catching her share of giant tuna!

*Disruptor*, doing what it was designed to do.

Since our last update in the spring, the electrical, navigational and all systems have been installed, and the boat’s final assembly took place—deck and hatches; cosmetics, fairing, painting, gelcoat, deck gear, and interior completion including installation of wood trim finish.

The Mussel Ridge 46 moved from our Newport build facility to the Safe Harbor Newport Shipard in mid-June and went in the water at the end of the month. First sea trial was two weeks later, after which the boat moved to Somerset, Massachusetts for two weeks of final trials before delivery to her owners.

The spacious, comfortable pilothouse and companionway leading belowdecks

The MR46 weighs in, lightship, at 30,465 pounds and when fully loaded is 47,265 pounds. That includes a couple thousand pounds of gear, 7,000 pounds of ice, 1,200lbs water, and 6,600 pounds of fuel.

After repitching the prop to maximize performance and carrying a full load, the boat runs at a cruising speed of 14.5 knots at 1775 rpm, burning 23 gph with 64% load on the engine. With the engine governed at 2300 rpm, the boat runs at 21.2 knots.

For specs and full designer comments, see below:

Pilothouse galley with additional multifunction display at the ready

Mussel Ridge 46 “Disruptor” Designer Comments

by Ezra Smith, chief designer, Newport Yacht Builders

We were approached by the client to develop/build an offshore fishing boat to be used for giant bluefin tuna fishing. The client is an experienced fisherman, but this boat would be a big step up from his current boat, a center console. Having fished on a number of different Downeast-style boats, he had some pretty well fleshed-out ideas about what he wanted. Large under-sole fish holds, three steering stations, integrated baitwell, greenstick and bandit reel, recessed trim tabs, a full array of fishing and navigational electronics—this was to be a very well kitted-out fishing machine. Fit and finish was to be simple and clean—not a lot of wood, durable and easy to clean, but finished to a very high standard.

Our client chose the Mussel Ridge 46 (extended 42) hull because this gets rave reviews from fishermen and lobstermen alike for its great ride and for hitting the sweet spot between performance and economy. To get it right, care must be taken to keep the build as light as possible, especially in the accommodations forward, as the added length in the stern shifts the center of buoyancy aft of the center of gravity (engine room/ mechanical space remains where it is on the 42); this means you want more weight aft and less forward.

Technical launch for *Disruptor* last June

We built the interior components from 3/4” thick foam and glass panels, with soles and bulkheads from 1” foam glass panels. We developed a full weight study of the boat, and weighed each component before it was installed, logging it in the weight study to track where we were. This was critical, both for tracking trim and to hit the target weight for the specified drivetrain. At launch, we were very close to our estimated weight, coming in it at 30,500 pounds dry.

For this build we went with a Scania DI16-007-M 1000hp engine with a Twin Disc MGX5136A 2.00:1 gear turning a Veem Star 36” 5 bladed prop on a 3” shaft. It pushes the boat along at 21.2 kts at 2300 RPM, with an owner-specified cruising speed of 14.5 kts at 1775 RPM, burning 23GPH.

The engine room and systems layout was carefully planned in advance.

On the systems side, we worked very hard with our partners, Ethos Marine Systems (electrical/electronics) and Buzzards Bay Boatworks (hydraulics, water, fuel), to lay everything out in the design phase. This was critical to our build process and made for an extremely clean, well organized systems layout.

Specifications:

LOA-45'11"

LWL-44'0"

Beam-14'10 1/2"

Beam @ Transom-13'6"

Draft @ DWL-4'11 1/2"

Displ. (Dry)-30,500 lbs

Displ (Full)-43,000 lbs

Fuel-850 Gal.

Water-150 Gal.