Selecting the Correct Size Outboard Shaft
The correct shaft length for your boat depends on a few factors. The first order of business is to measure your boat for the ideal fit. Once you know what will fit on your hull, you can fine-tune your choice based on the performance you’re looking for and how you use the boat.
Ideally, you want the outboard’s cavitation plate, also called the anti-ventilation plate, to be at the same level as the bottom of your hull. This will ensure the best performance. How the outboard will sit on the back of the boat depends on how the transom is designed. Some boats are equipped with transom-hung outboards while others have a bracket.
Having the cavitation plate too low will cause excess drag and reduced performance at high speeds. For slower boats, it’s less critical to