Once a year your boat trailer should have a thorough inspection, but in-between, give your trailer the once-over on a seasonal basis. This visual inspection will help make sure your boat doesn't end up sitting on the side of the road - something we've all seen before.
Now that you know what to look for every season, what gets added to the list for a more in-depth yearly inspection? Pull the bearings, and look closely for signs of wear and tear. Check out all of your wiring connections, from the tongue to the lights. Lean under the trailer and use a flashlight to illuminate areas like the inside of the frame and leaf springs, where corrosion take take hold. And give the brake system a complete once-over, to make sure the fluid reservoir is full and the hardware is in good shape. If you're not sure about how any of these parts should look, call in a pro and have a mechanic do the inspection, for you - because nothing is worse than having to leave your boat sitting on the side of the road.