If four out of five boats sink at the dock, that means the fifth boat sinks underway. Vincent Pica explains why for WindCheck magazine:
Before we get into the other percentages, why’s and wherefore’s, the single most reported reason is water coming aboard from the stern through the outboard engine cut-out. While fine for the bays, be extremely cautious about taking a boat so configured onto the high seas. A following sea can easily “poop” you from behind and overwhelm your capacity to off-load the water.
As to the other percentages and categories, roughly one in five sinkings at sea (18%) are due to direct leaks in the vessel itself, not caused by violent contact with the bottom or the sea itself. Areas of ingress, in order, are:
1. Through-hull fittings that give way.
2. Stuffing box leaks.
3. Knotmeter plugs.
4. Bait well discharge back-ups.
Roughly one in eight sinkings at sea (12%) are caused by raw (sea) water cooling and exhaust system failures. These parts, subjected to high heat from exhaust gases and the corrosive effects of salt water, simply wear out – and you are now pumping water from the sea into the engine spaces. Hitting something, often rocks, accounts for another 10%. Roughly one in 20 sinkings at sea (6%) are caused by excess force/excessive speed and the hull comes apart.
Source: scuttlebutt – https://www.sailingscuttlebutt.com/2021/09/07/why-do-boats-sink-at-sea/
