What activity is prohibited for persons on board a vessel?

Persons on board a vessel are generally prohibited from engaging in activities that pose a safety risk, such as operating the vessel under the influence of alcohol or drugs, engaging in reckless behavior, or failing to follow safety regulations. Additionally, activities that could lead to environmental harm, like dumping waste overboard, are also prohibited. Adhering to these regulations is crucial for the safety of all onboard and the protection of marine ecosystems.