1. A normal friend will respect your privacy and personal space. A boat friend grows accustomed to being in such close proximity to you, they never stray more than a few inches from you at all times, even on land.
2. A normal friend carpools with you to school or work. A boat friend rows, dinghies, SUPs, or just swims over to pick you up.
3. A normal friend will watch a movie with you on a bad weather day. A boat friend will come over and help you strip off outriggers, antennas, running rigging, and seal around hatches, ports, and lockers. They’ll make sure cockpit drains are free-running, the bilge pump and switch work, and that the battery is topped up.