Final answer:
The tongue weight should be around 10-15% of the total trailer weight to maintain stability during towing.
Step-by-step explanation:
In order to determine the percent that the tongue weight should be in comparison to the combined weight of the trailer and vessel, we need to understand the concept of the tongue weight. The tongue weight is the force exerted on the hitch by the trailer tongue. It is an important factor in towing stability. The general rule of thumb is that the tongue weight should be around 10-15% of the total trailer weight.
For example, if the combined weight of the trailer and vessel is 2000 kg, the tongue weight should be around 200-300 kg. This percentage ensures that there is enough downward force on the hitch to maintain stability, especially during braking.
Remember that this is just a general guideline, and it may vary depending on the specific towing setup and the recommendations of the trailer manufacturer.