When you get to the point where the vehicles are all checked out, you can focus your attention on loading. The two main rules of thumb for loading a trailer are: keep the weight of the load balanced both front to back and side to side, and maintain a low center of gravity. Because of this, loading boats can be a little different from loading regular trailers -- you have fewer options for where to place the weight since a lot of the heavy items are in predetermined locations, like the motors and engines. This is another reason why boats must be supported evenly by the trailer; it helps distribute the weight of the hull, engine and equipment in a safer fashion.
It may sound silly, but one important step in loading a boat is to make sure there isn't any trapped rain or other water stowing away on your boat. Water runs about 8 pounds (3.627 kilograms) a gallon, so if stormy weather recently passed through town, it may have thrown your weight calculations way off.
It's good when you're loading a boat, especially for the first time, to use a special scale to measure the amount of weight going on the hitch (i.e. not a jerry-rigged system that uses the little scale in the bathroom but one actually designed to measure thousands of pounds of weight). This can help you adjust the boat's position to make sure about 10 to 15 percent of the weight is on the hitch, because more or less can decrease stability and be dangerous. You can also use additional cargo to help balance the weight properly. If you do a bad job, the trailer may experience two dangerous phenomenons you never want to encounter: dive and sway. For more information on dive, sway and for tips on trailer weight distribution, check out How to Load and Unload Towed Vehicles.
Dual axles and weight distributing systems both can help make towing a boat safer. With two axles on the trailer, not only does this usually make a flat tire a little less harrowing, it also means you'll have an easier time distributing the load. A weight distributing system can also make loading easier, because it can spread around any extra weight that can't be handled by the hitch, moving a portion of it off the hitching system (and in turn the rear axle of the tow vehicle) and onto the front axle of the tow vehicle and the axles of the trailer.
There are a number of local and state regulations that concern boat towing, and once you arrive at the lake or the beach, what's the best way to launch your boat? To learn more about these topics, check out articles like Launching a Boat, as well as the links on the next page.