If you're taking a group of friends and family out, follow these tips to make sure you don't overload.
Capacity Plates On Smaller Boats
Boats measuring less than 20 feet and powered by a motor are required to carry a plate showing the manufacturer's designed capacity limits. Some manufacturers also provide capacity plates on boats up to 26 feet in length. This plate includes the boat's maximum capacity, usually in number of passengers as well as in total pounds, and may include maximum horsepower as well. Treat these numbers as an upper limit, and don't overly rely on them; if your boat was built before 2011, the capacity plate will assume an average weight per passenger of 160 pounds instead of the 185 pounds now in use. Keeping weight within the boat's capacity limit is key to safety.
Capacity On Larger Boats
If your boat doesn't have a capacity plate, your owner's manual or the manufacturer may offer guidance on how many passengers or how much weight your boat can carry. If not, one rule of thumb, used with caution, is to carry only as many people as there are fixed seats in the main cockpit of the boat; don't include seats in the bow or the flybridge in this calculation. If the boat does not handle well, feels sluggish, rolls excessively, or is taking water in through the scuppers, you need to lighten the load.
Even if your load is less than the maximum, poor weight distribution can still cause a capsize. Don't let everyone gather on one side or at one end of the boat to watch fireworks or help bring a fish aboard. The flybridge offers the best seats in the house, but four or five people on the flybridge with no one down below can cause even 35-foot boats to capsize. Have people take turns up top, and keep the number small enough that the boat doesn't heel or lean as they move around up there. Fore-and aft-weight distribution is just as important as lateral. Keep most of the weight in the center of the boat and as low as possible.
Total Built-In Seats
Don't assume that the total number of seats is the number of passengers you can carry or the best weight distribution for the boat. Many boats have seating in the bow, yet too much weight there while under way can adversely affect the boat's balance, its ability to plane, and your ability to steer while increasing the danger of flooding if you power into a wave or a wake.
Other Weight Distribution
A large cooler filled with liquid in the stern of a center-console boat can cause flooding from wakes or when backing down to bring in a fish. Take into account the levels of fuel and water tanks and bait/fish wells when deciding how you distribute the rest of the weight.
Adjust Weight Distribution Under Way
Proper weight distribution for your boat may not be the same when it is sitting still, running, or running on plane. If you experience poor trim, sluggish steering, or unusual responses when you turn the wheel, you may have a loading problem. Don't attempt to "correct" improper weight distribution with trim tabs. Stop and reconfigure the weight.