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What You Need to Know About Boat Capacity Plates

Ian Fortey by Ian Fortey Updated on April 24, 2021. In

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A large number of deaths and injuries on the water are caused by overloading boats. There were 57 deaths in 2019 alone as a result of this. Many boaters are not aware of the capacity of their boat. They are unfamiliar with capacity plates. Some boaters do not know what their boat capacity plate states.

Let’s take a look at where to find your boat’s capacity plate. Also, how you can figure out your boat’s capacity if you have no plate, so you and your passengers can stay safe.

What is a Capacity Plate?

Boat manufacturers are required by federal law to include a capacity plate. This plate must be visible from the boat’s helm or steering area if the boat is less than 20 feet in length and motorized. Kayaks, sailboats, canoes and inflatables are exempt from having to have a plate. The capacity plate details the following;

  • The boat’s maximum horsepower
  • The maximum number of people and/or weight in pounds
  • Maximum weight capacity of all people, gear, and motor together in pounds.
  • The boat manufacturer
  • The boat model
  • A serial number may also be included

There are several different designs for capacity plates. Older plates had a different look to them as well. The information was detailed differently. For instance, some plates may have had a line for maximum people. This would be followed by a line for maximum weight. Now these are often combined as one line. The next line offers maximum weight including the engine and gear.

The capacity plate should also indicate that the boats meets U.S. Coast Guard safety standards.

What If There is No Capacity Plate?

The law governing the use of capacity plates came into effect on August 1, 1973. If you have old boats then you won’t have a plate. Likewise, if you made your own boats then it won’t have a plate. There is a formula you can follow to learn how to calculate capacity.

Why is Horsepower Capacity Listed?

The horsepower on a boat capacity plate is very important. An engine that is too large for a boat can be a danger. It may seem like a fun idea to be a huge engine on a small boat to make it fly. The problem is a larger engine can be too heavy. You may end up weighing down the stern so badly that the boat flips. If it doesn’t flip, you may cause the transom to dip too low. You could take on water and capsize.

Why Is Weight and Number of People Listed?

The weight limit is obvious. But some boaters wonder why there is a maximum capacity for passengers as well. It’s because people are very unpredictable. If your boat can handle 1000 lbs, then 1000 lbs of gear is very easy to load safely. However, a 1000 lb person capacity would not be. People move around. Their center of gravity shifts. They may all congregate at one side of the boat. Too many people can cause more problems than just too much weight.

The other thing to consider is that people obviously do not have consistent weight. For the purposes of a capacity plate, a human’s weight is averaged to 150lbs. So if you have passengers who weigh much less or much more, it can skew that particular figure. That’s why there is a strict person capacity weight limit regardless of the number of passengers.

Your gear must be balanced. Even if the boat’s capacity is 1000 lbs, it can’t all be at the bow, or on the port side. Even distribution is very important. That will keep the boat running smoothly. It puts less strain on the engine and makes handling easier.

  • A heavy bow will cause the boat to plow into the water. This slows progress considerably. It strains the engine and may cause you to take on water.
  • Too much weight to port or starboard will cause the boat to list. Another boat’s wake could cause your boat to capsize. You may also start taking on water.
  • A heavy stern can flood the engine. You can sink the transom and capsize as well. Plus there is the risk of flipping the boat or a man overboard situation.

Make sure all passengers have adequate seating. Keep people off the transom or the bow, especially if you’re getting close to capacity.

National Marine Manufacturers Association Standards

Some boats carry a NMMA plate. These list standards beyond the capacities listed on a capacity plate. That includes info about fuel navigation lights, steering, maneuverability, and more.

Capacity Plates Aren’t Absolute

An important thing to remember about your boat capacity plate is circumstance. These numbers are under ideal conditions. That means calm seas. If you’re out in a storm on rough seas, the situation changes. If you’re at capacity and a storm hits, it could be very dangerous. Get to shore as quickly and safely as possible in such a situation.

If you have an idea that the weather may turn bad, prepare accordingly. Pack light, just in case. Remember that waves can get quite high in a storm. On an overloaded boat, it can be easy to get swamped.

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1 Comment

  • Ken Donnelly on September 14, 2020

    I have a 24′ X 10′ home built tritoon. I want to power-up the tritoon with at least a 200HP, do I need a capacity plate? If so, how do I go about getting this tritoon re certified with a new plate?

    Reply

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