Two of the least checked items are ones that can lead to problems – drains and thru-hull fittings. Failure to correct what seems like a minor item can result in a vessel sinking.
No boater wants to receive the message — “Your boat sank”.
Boats have various self-bailing features designed with drains in the deck, usually near the stern and most often covered by a screen-like cover. If not checked regularly, they can become self-filling.
A hose connects these drains under the deck that runs down to the thru-hull fitting. A crack in one of these hoses allows water to drain into the bilge. If the bilge pump fails, water accumulates, the boat settles below the waterline, and the thru-hull fittings allows water to enter. The lower it goes, the faster it will sink. 
If the deck drain hose is cracked, the most common reason for a vessel to sink is ordinary rainwater. Water designed to emit out the thru-hull fitting is now accumulating in the bilge.
Another cause could be from washdown pumps. If you leave your vessel unattended with the pump switch in the “on” position, and if a leak develops, water will flow freely about the deck and into the bilge if the drain hose is cracked. The bilge pump will cycle, the battery will run down, and could cause your boat to sink.
A smaller boat running in choppy seas with a crack in one of the self-bailing hoses, allows a great deal of water to accumulate in the stern. If an operator notices his boat handling oddly and stops to check, water will rush forward and flood the engine causing the boat to stall.
Spring is an excellent time to take a few minutes to check the condition of the hoses, drains and thru-hull fittings.
