Final answer:
Seaplanes are required to carry life jackets for each passenger on board as a standard safety equipment, essential for emergency situations.
Step-by-step explanation:
Seaplanes must carry several safety items on board, but the item specified as a requirement by international aviation regulations and various national authorities as a standard safety equipment is life jackets. These are essential for ensuring passenger safety in the event of an emergency landing on water. While anchors, flares, and paddles might also be carried depending on the operation and local regulations, life jackets are universally required for each passenger aboard seaplanes. It's important for pilots to check and maintain all safety equipment regularly, and passengers should be briefed on how to use these items before takeoff.