What must you have on board while operating a vessel?

While operating a vessel, it is essential to have a valid registration document, proof of insurance, and a life jacket for each person on board. Additionally, you should carry safety equipment such as flares, a fire extinguisher, a first aid kit, and navigational tools like a compass and charts. Depending on the size and type of vessel, other equipment may also be required, such as a sound signaling device or a throwable flotation device. Always check local regulations for specific requirements.