Sea Catch History

As with most innovations, Sea Catch was spawned from a problem solving effort. In this case, a quandary presented itself to Bob Schmidt, a commercial set net fisherman, on the eastern shore of Alaska’s Cook Inlet in the mid-1980. Here, all salmon fishing set nets are located on the beach or near the shoreline. The set net consists of a floating cork line and a heavy lead line with salmon gill-netting hung between these lines. These nets are anchored at each end to the sea floor and/or to the beach uplands via heavy posts and a pulley.

Generally, the nets are set and removed from the water at specific times, but the fish caught are typically picked at slack tide by fishermen using skiffs (see photo above), since the tide moving through the inlet creates a powerful current that runs parallel with the shoreline. During the summer fishing season, fishermen are often required by law to remove their nets from the water by 9 PM. Although there is a large float (buoy) at the outside end of the net and corks along the full length of the cork line, the entire net and its flotation system is prone to being submerged when tides are high and currents are strong (see illustration below).

If such conditions are anticipated at the 9 PM removal time, fishermen would go out at the 6 PM slack tide, pick the fish and remove the gear from the water to avoid the high tide hardships and possibly a fine by the Alaska Department of Fish & Game for having gear in the water beyond the 9 PM deadline. But this mean the loss of 3 hours of valuable fishing time. In addition, in most cases, heavy salmon runs occur during these high tide situations.

So, the question arose, “For these conditions, how can we leave the net in the water right up to the 9 PM deadline and pull it out on time?” Not only would you get 3 hours of extra fishing time, you would also have access to all the fish along the beach for that entire period since other fishermen would have removed their nets at the 6 PM slack tide time.

It seemed that an ideal solution would be to install two release devices to one end of the net at the 6 PM slack tide time. One device would be attached to the cork line and the other to the lead line and these would encircle (grab) the pin of a shackle connected via lines to the anchor. The nets eventually become submerged. Just before the 9 PM deadline, the net would be disconnected from its anchor by releasing these devices (the devices stay connected to the net). A floating pull cork on the upper end of a 20-30 foot release lanyard (line) leading via a “Y” to each release, would ensure that the fishermen in the skiff would have access to it at all times. Once the cork is pulled, both devices release the net from the anchor, and the entire net with all its fish would flag out with the current and be hand-hauled into the skiff just before the 9 PM deadline. Later, the fish would be picked from the net on the beach.

After experimenting with pin shackles and pelican hooks, the only thing that worked was a primitive device based on a modified set of Vice-Grip® pliers. These devices use what is called a four-point toggle linkage principle to grip and lock anything within its jaws. The jaw here was replaced with one that encircles a metal pin or ring rather than gripping it. The body of the device was fitted at the rear with a hole where it could be connected to the net. The release lever was modified with a hole where the release lanyard could be attached. Two units were required, one for the cork line and one for the lead line. This may have been the first times in history that a four-point toggle linkage was used in a locking and releasing device!

The device shown above is one that Bob Schmidt originally used on his nets. It was designed and manufactured (between 1986-89) by Travis Pattern and Foundry of Spokane, WA (which is still in business as of 2026). Bob paid $96 per unit. They were cast of silicone bronze. John McMillan, who worked as a crewmember on Bob's beach operation for several years, clearly recalls the day when a set of these releases were used during a high tide and a submerged set net full of fish, and was amazed how well it worked.

Since John had learned how to draft patent disclosures, including the claims and drawings, Bob Schmidt asked him to prepare and file a patent application in 1986. It was titled, ”High Tension Quick Releasing Toggle-Locking Connecting Device”. Since Bob did not respond to the USPTO in a timely manner, this application was abandoned and likely rendered invalid. In addition, the One-Year rule bars one from obtaining a valid patent on an invention that has been published and/or publicly used for one year. Bob Schmidt declined to pursue protecting his device with a patent.

When the Exxon Valdez oil spill closed the Cook Inlet Fishery, John became a crewmember on a purse seiner in Prince William Sound in the summer of 1990. Bob gave this particular well-used unit to John when John found the pelican hook skiff release being used was clunky, noisy and had a kick-back. In salmon purse seining, the heavy skiff is towed around until a set is to be made (see illustration above). Here, typically, the skiff’s painter is latched to the quick release which is on top of the stacked purse seine net. The rear end of the release is connected to the vessel’s capstan. When a set is eminent, the deck hand pulls the release lanyard, releasing the device and and allowing the skiff to reverse, turn around and pull the seine net off the vessel and into a arc-shaped formation to catch salmon. It worked so well that it was used the entire summer for many release cycles. Most purse seiners in Alaska now use the Sea Catch TR7 device for this application.

Since the release portion (jaw) of Bob’s device sustained the entire load, a compression spring retainer on the release lever was required to prevent damage when the lever was propelled into the open position with great force during release.

So, John spent the next several years relentlessly designing and prototyping toward a stronger device, knowing release applications in other industries would entail heavier loads. Money for this prototyping was obtained by doing handyman work in the greater Seattle area.

One patent John obtained in March 1992 disclosed the device shown above. It was cast of silicone bronze. A set of pivoting retainer bars kept the release lever from the shock of being thrown out and getting damaged. While the extension spring on the release lever dampened shock, this prototype did not stand up to heavy tensile loads due to it being cast. Cast parts, he would learn, are notoriously inferior in strength to components made of steel.

Later, an attempt was made to strengthen the jaw portion with stainless plate material as shown above, but this did not provide sufficient strength since the remainder of the parts were cast. Improvements, though, were the retaining bars which kept the release lever in check, the release lever was set at an angle which allowed the unit to be released from multiple directions. Most importantly, the body of the device shared the load with the jaw, thereby greatly reducing the load and stress on the releasing portions of the device.

So, ultimately, casting would not be the solution to the manufacturing process. And if one were to cut parts from steel plate, AutoCAD would be needed. Fortunately, John had completed his two-year course in Industrial Design Technology at the Art Institute of Seattle in the fall of 1992 where he learned CAD. Waterjet technology was the new thing - where high pressure water mixed with garnet is used to cut through plate steel and other material using digital profiles created in CAD. He also learned that a waterjet-cutting company start-up was looking for some industrial design work for illustrations of their new product. John found himself in a desirable position of getting his parts cut out during the beta-testing of the waterjet machine, thereby saving him money.

This process was used for the prototype shown above where the waterjet-cut parts were welded together. The load connection holes at each end were sized to receive the pin of a common shackle. However, the 300 series stainless steel used here was too soft for heavy loads. Under pull-testing, the unit did not break, but began to deform at 18,000 pounds. Any deformation would alter the critical pivot pin locations and render the device inoperable.

John found out about a stronger stainless steel material called PH 17-4. This material does not deform until very close to the peak of its breaking strength – ideal for a release device that is to be met with heavy loads and whose integrity needed to be kept in tact throughout many release cycles. This material is typically heat treated to 1025* to further strengthen it.

He had a model TR7 cut out, welded up and assembled with 17-4 pivot pins (shown above). It passed the test with a very desirable 35,210 pounds of load before breaking. This test revealed that a unit weighing only 4 pounds had a safe working load (SWL) of over 7,000 pounds! This load also coincided with the SWL of the common shackles used with the model TR7. Larger pivot pins were improvements as were retaining rings to ensure they remained in place. Another improvement was the addition of a hole formed through the toggle linkage plates and the release lever which receives a hitch pin (not shown in this image) for locking up the device when not in use and preventing inadvertent release.

Added to the design was a wider body portion at the center of the base which assists with the mounting of air or hydraulic cylinders for applications requiring remote activation. Two small holes are formed in the body where a label can be riveted to the body.

On May 11, 1999, the patent for this final design (shown above) was awarded to John who has, to date, 6 patents to his name, 4 of which relate to the toggle locking principle.

One large benefit to this approach is that the design can be digitally scaled up or down, depending on the shackle size used for any particular release application. With cast parts, one would have to build a separate pattern for each model which greatly increases production costs. Also, the digital process offers the ability to easily modify units for special applications.

Up until 2010, John work out of his small daylight basement in Gig Harbor, Washington (see photo above, taken in 1999).

He presented several models of his Sea Catch Toggle Release at his booth at the 1999 Fish Expo in Seattle (see photo above) where many workboat owners and commercial fishermen first learned of this new device.

The first commercial sales were to the sea technology sector in the fall of 1994. Even after 30+ years of use, Sea Catch is still the only quick release device in the world that uses the toggle linkage principle to safely secure lines or objects under load. Sea Catch models now accommodate shackle sizes ranging from .65 tons to 77 tons SWL.

Many industries throughout the globe, in both the private and military sectors, use the Sea Catch device for critical release applications. This device will outlive John who has sold the company in December 2025 to Ryan Cole who has worked at McMillan Design, Inc. since 2018 and who has steadily enhanced many aspects of the business with his skills.

-- JM 01/2026