Brand new Bristol Bay boats built by Mavrik Marine - each one is outfitted with an IMS RSW system.

Brand new Bristol Bay boats built by Mavrik Marine - each one is outfitted with an IMS RSW system.


As the first person that touches the catch, you, the fisherman, are the first link in the cold chain. Fish that are chilled at the point of harvest and handled carefully, command a higher price. If you sell to a processor this may even be a requirement. If you direct market your catch, it’s an absolute necessity. You may also work multiple fisheries with the same vessel requiring you to adjust your refrigeration configuration. We offer a range of products that meet the needs of different fisheries, species and gear types. We have designed systems that work for these types of seasonal conversions and also build units that are capable of both onboard chilling and freezing.

Chilling Onboard

A self-contained RSW system may be the answer for one vessel and a condensing unit with a remote-mount chiller the better choice for another. From large trawlers to compact gillnetters – and everything in between – we have the experience and know-how to help you find the most practical and cost-effective solution for your vessel. 

Freezing Onboard

Blast freezers hold product at lower temperatures (-20 to -40 degrees) than brine freezing. Commonly used onboard for tuna, salmon, shrimp, crab and scallops, blast freezing provides rapid deep freezing. IMS manufactures Hatch Mount Blast Freezers (HMB) that easily drop on and off vessels, as well as low temperature condensing units with remote mount evaporators. To increase freezing capacity, some vessels will opt for brine freezing in addition to a blast freezing system.

A brine freezing system is similar to those used for RSW, and is used primarily for fish to be frozen whole, such as salmon and tuna. Since it takes lower temperatures to freeze the brine (a salt and water mixture) than the fish, the fish are frozen but the water is not. Holding fish in a brine mixture requires less handling than a conventional freezer - meaning high quality fish and less labor input. The catch is chilled quickly, and uniformly, and the ideal temperature is maintained over the length of the voyage. Brine systems eliminate the slow and fatiguing work of shoveling ice and layering fish. In addition, brine freezing eliminates the need to travel to replenish ice, as well as eliminating the added bulk and weight of ice - thus conserving fuel and reducing costs.

The F/V Saga & F/V Columbia tied up in Dutch Harbor.  Photo by Jeff Pond / JP Images.

The F/V Saga & F/V Columbia tied up in Dutch Harbor. Photo by Jeff Pond / JP Images.

Working Multiple Fisheries

With fluctuations in market prices due to pressures from imports – plus changes in fish stocks that can close entire fisheries, it is increasingly important for fishermen to be flexible in order to prosper in these challenging times. We build products that can adjust or be converted to suit the needs of fishermen working multiple fisheries from the same vessel.

A removable deck-mount RSW system that allows for seasonal conversion means that, for example, a vessel can work both as a crab boat and salmon tender. Our HMB Freezers can be installed on deck for blast freezing tuna, for example, and removed after the season to ready the vessel for another fishery. A Combination Chilling/Freezing System means that a vessel can tender in Alaska and also have the capability to blast freeze specialized product for direct sale to high-end consumers.

Live Seafood

Certain products, like crab and lobster, require live delivery. Holding live product onboard requires temperature control, aeration, water re-circulation and the use of titanium, rather than copper nickel, chillers. We have experience in multiple fisheries with live delivery systems and a track record helping fishermen deliver quality with near zero dead-loss.