Fishing Vessel Stability Requirements—Adding Clarity to the Murky Applicability

Vessel undergoing a major conversion, 2019. USCG photo.

This is the second article in a three-part series on the topic of fishing vessel stability.

Last month’s column covered awareness and training and next month’s will address operational stability and how the use of a vessel can drastically affect its stability. But this issue’s article focuses on regulations and requirements and how some in the industry and even the Coast Guard, fail to recognize when they apply.

What, When, Who? – Does This Apply to Me?

When it comes to commercial fishing industry vessels 79 feet or greater (that are not required to have a load line), the stability rules are within 46 Code of Federal Regulations Part 28, Subpart E (Stability). You can look up those on your own if you want to read it word for word.  They are most helpful if you are having difficulty falling asleep; just read a few columns of a CFR and you’ll be out in no time.

Deciphering whether your vessel needs to meet this section is not always glaringly obvious.  To summarize, in general, stability regulations apply when a fishing industry vessel meets any one of the following thresholds:

New vessel with a keel laid date of Sept. 15, 1991, or later.

An existing vessel that does a ‘major conversion’ after Sept. 15, 1991. A major conversion is determined by the Coast Guard’s Marine Safety Center and could be when a vessel changes service, let’s say a Gulf of Mexico oil-service vessel changes over to a fish tender. Or it could be when a vessel’s dimensions substantially change, such as sponsoning or lengthening.

An existing vessel that changes the fishing or processing equipment in a manner that wasn’t done before. An example could be a vessel that was designed to fish with pots, and it later adds trawling gear.

An existing vessel that, after Sept. 15, 1991, undergoes any variety of a wide range of changes or an accumulation of small changes that in turn affects the vessel’s stability can trigger stability applicability. This is the hardest one to recognize and is often missed. Let’s dive into this a little deeper.

The key term here is “substantially altered.” The regulations define the term, but in essence, it means a change to the vessel’s dimensions or a two-inch change in the vessel’s vertical center of gravity (VCG), 3% change in lightship weight or shift in the vessel’s longitudinal center of gravity (LCG) of more than 1% of the vessel’s length. English, please!

Some naval architects include this information in their stability books with a clear explanation “a two-inch increase in the VCG is equivalent to adding 14,000 lbs. at the height of the shelter deck amidships. A 3% change in the vessel’s lightweight displacement is adding or removing 20,450 lbs. An example of shifting the LCG is moving an object weighing 12,000 lbs. 50 feet forward to aft.” Much better when it’s explained in terms easier to understand.

When to Update?

Vessels that already have stability books still need to be mindful of when a vessel’s stability needs to be updated.

Besides the same thresholds listed above, changes in a vessel’s lightship weight need to be watched carefully. Almost all vessels gain weight over time. Accumulation of spare parts, changes in accommodation, rooms, paint, etc., it all adds up.

A good rule to follow is to do a stability review every five years. Keep track of all weight changes to the vessel in a book, spreadsheet or log. Record the weights added, removed and relocated. But keep in mind that the tally you’re keeping is the aggregate weight (sum) of all those changes.

Take the installation of a new galley stove for example. You remove the old stove that weighed 200 pounds and installed a new one that weighs 175 pounds. This is considered a 375-pound aggregate weight change. The Marine Safety Center issued Technical Note No. 04-95, Ch-2 that explains when a vessel’s aggregate weight change reaches 2% of the lightweight displacement, then the stability should be reevaluated.

This could be as simple as what is called a weight-moment calculation or a new deadweight survey, or, if it reaches a 10% weight change, a full stability test. There are additional provisions that apply to this, so please consult a naval architect.

Who’s Responsible?

For a tightly run vessel, everyone is responsible to follow and maintain the vessel’s stability.  But the rules specifically place heavy responsibility on the owner. They are the ones tasked with hiring a competent and qualified person to perform the tests and calculations. But how do you select someone who meets those criteria?

There are several professional naval architect firms that are very good at what they do.  They are very meticulous, address every detail, insist on accuracy and when it comes to presenting the stability information, they continuously make improvements to the layout, terminology, graphics, etc. to meet the needs of fishermen.

The losses of the Destination (Feb 2017) and Scandies Rose (Dec 2019) have rekindled conversations about vessel stability. Many owners have taken the initiative to have their stability updated. Some have sent their skippers and engineers to a training class. When they consider vessel modifications, they engage a naval architect early in the process. All good stuff.

But there are other owners who wait for the Coast Guard to tell them when and what needs to be done. Not always a good idea; even the Coasties miss it sometimes.

What Can You Do?

Take the initiative and own it. Make vessel stability more than just a box to check—make it a priority. Hire a reputable naval architect with experience with the fishing fleet. Send your skipper and engineer to a training class. Dig into your stability report, engage with the naval architect to explain the information, or change the way it is presented so you and the folks onboard can understand it. Maintain the water integrity of the vessel. That includes the hull, any penetration, the watertight deck, vents, hatches, doors, windows, etc.  

Next Month: Operational stability. Bringing it all together, plus a pre-departure stability checklist.

Mike Rudolph is a Fishing Vessel Safety Examiner and trainer with the U.S. Coast Guard based in Portland, Ore. He is an AMSEA-certified drill instructor and fishing vessel stability trainer. His passion is to help fishermen reduce the risks involved in their occupation so they can return safely to their families or the people that owe them money.