12. Generator Cooling Intake
What Happened: The hose cracked, water flooded, boat sank. I hope you're picking up a pattern here about hoses.
What You Should Have Done: Use series 135 heavy-duty water hose-no exceptions. It resists chafe, is reinforced to prevent collapsing, and has a working pressure of up to 200 psi. Wiggle the hose where it meets fittings to look for cracks. Rub a damp cloth along it. If there are black marks on the rag, the hose is deteriorating.
13. Head Intake
What Happened: An unprotected head-intake hose running through the engine room bulkhead chafed, then failed.
What You Should Have Done: Do your hoses make as few bends and turns as possible? They should be secured tightly and padded where appropriate.
14. Head Intake II
What Happened: The water-fill hose connecting the outside of the hull to the head crapped out. The head, being below the waterline, filled and so did the boat.
What You Should Have Done: Besides maintaining the hoses and clamps, make sure the boatbuilder has left easy access to the inlet's seacock. Make it a policy that when you leave the boat, you shut all the seacocks. Then, if a hose fails, it's no big deal.
15. Head Discharge
What Happened: The one-way joker valve on the head's discharge got something in it. You were smart enough to run the discharge hose above the waterline to keep water out but not smart enough to remember how a siphon works. Trying to siphon the full contents of the Atlantic Ocean, your boat soon sinks.
What You Should Have Done: To prevent a reverse flow, when you run any hose above the waterline, remember to install a vented loop fitting at the top of the loop. This lets air in to prevent a siphon. Use fittings that let you disassemble the valve each season to make sure it's clear and working.