The most likely causes for someone to fall overboard include:

• Slippery decks due to ice, spills, fish slime, or rain, which cause loss of footing especially in rough seas.
• Human error such as distractions, fatigue, poor judgment, lack of experience, and impaired coordination from alcohol or drugs.
• High winds and unstable footing conditions on the deck.
• Unsafe boat operations like speeding, sudden maneuvers, or poor planning leading to imbalance.
• Lack of proper safety equipment and inadequate railings or structures.
• Recreational activities that increase risk without precautions.

These factors are common on cruise ships, small boats, and other vessels, often combined with environmental conditions and human factors that impair alertness or judgment.