What does a capacity plate indicate

Boating always involves some amount of risk, which is why following safety precautions is so vital. In general, following those guidelines keeps you safe and allows you and your passengers to enjoy water recreation. And the first place to look for helpful safety info is right in your boat. The boat you own (or the one you plan to buy) likely has a little metal plate with essential numbers on it. If you’re wondering what useful information can be found on a capacity plate, the answer is, a lot! Read on to find out more about capacity plates, including which boats have them and what to do if yours doesn’t.

As the name suggests, a capacity plate indicates the maximum capacity for a water vessel. Plenty of other information appears there, as well, and that’s due to a 1973 regulation from the U.S. Coast Guard. The legislation required that mono-hull boats shorter than 20 feet display a plate posting crucial passenger and other ratings.

Which Types of Vessels Have Capacity Plates?

Many larger boats feature capacity plates or have other signage to indicate safe passenger limits. But per the U.S. Coast Guard, boats under 20 feet long must have a capacity plate unless they are one of the following:

• A sailboat
• A canoe
• A kayak
• An inflatable boat

Although the above types of watercraft do not commonly have capacity plates, the manufacturers will specify limits and guidelines in the user manual. In general, a sticker or another kind of warning will be present on the body of the vessel. If not, investigate the user manual or the brand’s website for help.

A boat with a manufacture date pre-1973 may also lack a capacity plate. In that case, you can still calculate the capacity for the vessel—or contact the manufacturer for assistance.

Where is the Capacity Plate?

You can find your boat’s capacity plate near the helm of the vessel. Your boat’s helm is wherever you steer from, which will vary depending on the type of boat and how it operates. For example, boats with outboard motors have a “helm” near the stern (rear). You might find the capacity plate on the boat’s transom (the back “wall”). In boats with a cockpit, the plate may be within eyesight as you steer the boat.

On vessels shorter than 20 feet, the plate will carry the label “U.S. Coast Guard Maximum Capacities.” Boats from 20 to 26 feet long have wording which states only “Maximum Capacities.” Both size ranges have yellow plates with a silver background. Variations exist in the style and layout of the plates, as designs have changed over the years, but most have the U.S. Coast Guard logo. In some cases, the manufacturer logo is more prominent than the other information, but some plates lack branding information altogether.

Another Type of Plate

Some boat manufacturers also apply for certification with the National Marine Manufacturers Association. These types of plates highlight other information about your boat.

The NMMA examines and certifies models of boats and yachts (among other products) to provide safer products to the boating industry. If your boat has the NMMA certification, that means it has passed a detailed inspection process. 

The NMMA certification involves a special capacity plate with details such as certification of navigation lights, flotation devices, maneuverability, and other features. Power boat manufacturers do not have to participate in the program. However, they must follow the regulation for standard capacity plates.

Primarily, a capacity plate dictates how many passengers (and what weight) the boat or personal watercraft can carry. However, it also contains much more information on safety and vessel operation. So what useful information can be found on a capacity plate? We’ll list details here.

Maximum Passengers

The “maximum persons” notation refers to how many full-size adults the watercraft can carry. However, the calculation manufacturers use for this limit can be deceiving. In most cases, boat manufacturers assume an average adult weight of 150 pounds per person. Factor your passengers’ weights into the equation to determine whether the maximum passenger limit is realistic for your guests.

Maximum Gross Load

The maximum gross load includes the total weight of all passengers. The number on the capacity plate can also give you an idea of what the manufacturer assumes each adult’s average weight is. Use the figure to calculate the per-person weight limit for your party.

In addition to following the guidelines for load limits, you should also aim to distribute the load evenly. Balancing passengers and equipment can keep your boat more stable and avoid capsizing.

Persons, Motor, & Equipment

You can estimate the overall weight by adding together the average weight of your passengers plus your equipment, fuel, supplies, and any other goods on the vessel. Because it can be difficult—if not impossible—to determine the exact weight on board, it’s helpful to look at how your boat sits in the water. If either the bow (front) or stern (rear) dip low in the water, that’s a sign you have overloaded.

Maximum Horsepower

On power boats, the placard contains maximum horsepower details. However, the placards do not specify horsepower for inboard or stern drive motors. Similarly, for manually propelled boats, there is no listed horsepower specification.

Manufacturer Information

Though the three previous figures are most crucial for a safe boating experience, the placards also include manufacturer information. You will likely find a manufacturer name, production date, and model number (or any combination of the three) on your boat’s plate.

If your boat is under 20 feet long or is a specific type of watercraft—such as a kayak or inflatable boat—it may not have a capacity plate. Or, if your vessel is older or you bought it used, the plate may have fallen off at some point during previous ownership.

In most cases, you don’t need to worry about the plate if you can determine the weight limits and horsepower without it. But you may need those details to obtain boat insurance, depending on the type and size of the vessel. Insurance coverage and pricing varies widely but having these specs can help you obtain coverage.

Even without a capacity plate, you can calculate the safe load weight for your boat. For mono-hull boats which measure fewer than 20 feet, you can use the length of the boat and multiply it by the boat’s width. Then divide that number by 15 to determine how many passengers you can safely carry. Personal watercraft use a different calculation for capacity. If your PWC doesn’t have a capacity plate, check your user manual or contact the manufacturer for details.

Keep in mind, however, that even boats with a posted limit specify such limits in good weather. In stormy or otherwise difficult water conditions, it’s wise to travel light or even stay on the shore instead.

While guidelines are in place for a reason, it’s unclear whether a boat operator can receive a ticket for overloading a boat. In most cases, authorities patrolling the waterways tend to stop boats to check for safety features like life vests. But authorities can issue citations to boaters, though legislation varies by state and even by waterway.

Of course, the primary risk of not following the posted capacity rules is you could damage your boat or put your passengers at risk. An overloaded boat has a higher risk of capsizing, which could not only endanger the people on the boat but also people around you on and in the water.

Plus, flipping your boat over could damage the cockpit and other areas of the deck. You could lose your belongings, too. So while it may be inconvenient to limit the number of passengers you transport on your boat, it’s worth the safety risk to stick to the thresholds on your capacity plate. You may also avoid getting a potentially expensive citation from local authorities.

One of the most important things you need to know before setting out on the water is the maximum number of people and maximum amount of weight that your boat can safely handle. Not only is this an important safety concern, it's also the law.

Federal Law mandates that all powerboats less than twenty feet in length need to carry this information in the form of a Capacity Plate.

Each Capacity Plate includes the maximum number of adult persons, the maximum gross load, and the maximum size of engine, in horsepower, that your boat can legally carry.

The next time you're around a boat, look for its Capacity Plate; it should be permanently fastened near the steering area, or the helm.

Before any boat trip, you'll want to make sure that you are not taking more people onboard than is indicated by the Maximum Person number, and that you don't have more total weight than is indicated by the Maximum Gross Load. The Maximum Gross Load is the total weight your boat can handle, including people, equipment, stores, fuel, engine assembly and steering controls. If your boat doesn't have a Capacity Plate, you can calculate the number of people you can safely take onboard using the following equation.

If your boat doesn't have a Capacity Plate, you can calculate the number of people you can safely take onboard using the following equation and calculator.

Number of people = vessel length (ft.) x vessel width (ft.) ÷ 15

First, find out the length and width of your boat in feet, then use our calculator to find out your boat's capacity.

Note that personal watercraft do not have a capacity place. For P-W-C's, always follow the recommended capacity in the owner's manuel and on the manufacturer's warning decal.

Finally, the Capacity Plate will also indicate the maximum engine power for your boat, given in horsepower. This number applies only to boats powered by outboard engines; and it must never be exceeded.

Maximum Person Capacity

There are a number of variables that boat manufacturers consider when determining the maximum person capacity that appears on your Capacity Plate.

One of those variables is the weight of each person.

Boat manufacturers typically use an average weight of about one hundred and fifty pounds per person to calculate maximum capacity. It can be a little more or a little less, but if some or all of your passengers weigh over one hundred fifty pounds, you may have to decrease the number of passengers you can safely take on board.

Remember, the maximum person capacity is a guideline that you have to adjust given the weight of your passengers and the other supplies you are taking on board.

If you are carrying heavy equipment, you may have to further reduce the number of passengers.

Maximum Horsepower

If you don't have a capacity plate on your boat—which may be the case if you're operating a small, flat-bottomed boat—you can calculate the largest safe engine size in the following way.

Maximum Horsepower Calculation: Boat length x boat width = boat square footage

First, find out the square footage of your boat by multiplying its length by the width of the transom.

Remember, the maximum person capacity is a guideline that you have to adjust given the weight of your passengers and the other supplies you are taking on board.

Then use our calculator and the table here, to find out your boat's maximum horsepower. For example, a twelve-foot boat with a four-foot transom width translates into a maximum engine size of fifteen horsepower.

Overloading or Overpowering

Either overloading or overpowering your boat is extremely dangerous.

Putting an over-sized engine on your boat will cause your boat to sit too low in the stern, and that will make it much more susceptible to being swamped by its own wake or that of a passing boat. An overpowered boat is also hard to control.

What about overloading your boat? Overloading your boat, either with too many people or too many supplies, also makes your boat susceptible to swamping.

Even if you are within the maximum allowable weight, make sure that you distribute the load evenly, focusing the weight in the middle of the boat. This will keep your boat stable in the water and help prevent capsizing or swamping.

Finally, remember that in bad weather, you must be extra careful about how much weight you take in your boat. With higher waves, a heavy boat is harder to control and more susceptible to being swamped. Stay safe. Follow the guidelines for load capacity and always adjust for bad weather.

Beware of bad weather! Take much lighter loads in poor weather conditions to ensure boat stability.