The Common Causes
• Hose clamps: Winterizing an engine in the fall often requires the removal of coolant hoses. Come springtime, boaters are in a rush and the hoses aren’t reattached and clamped properly. Adding to this, cramped engine boxes mean that the hoses and the clamps holding them sometimes can’t be visually inspected easily. In the spring you’ll need to ensure all of the hose clamps are securely tightened in place.
• Hoses: During the winter as the water inside them freezes, some hoses can lift off their attached seacock (valve). However, with spring’s warmer temperatures the water now returns to a liquid, and if the seacock was left open last fall, water can pour into the bilge. Double clamping with marine-rated stainless hose clamps, inspecting hose attachment locations, or keeping seacocks closed can all save you from a spring sinking.
• Spring rains: Combine heavy rains with leaking ports, deck hatches, fittings, chain plates and even scuppers clogged by leaves from last fall and you have a recipe for a sinking. Just 100 gallons of water weighs over 800 pounds so a boat with a low freeboard only needs to sink a few inches before cockpit scuppers (drains intended to remove water) submerge and water starts to enter the boat. Larger boats with cracked or improperly caulked fittings that are located just above the waterline can also inadvertently let water in when they become submerged. Ensure that rain rolls off the boat and not into it.
• Sea strainer: For inboard/outboard and inboard powered boats, always inspect the strainer for cracks or other damage. If it wasn’t properly winterized, the intake sea strainer could have frozen over the winter, cracking or bending the inspection bowl. And if the seacock was left open the boat will sink as soon as ice in the strainer thaws or the boat is put in the water. Boats have also sunk when the seacock was closed over winter and then opened in the springtime, but the owner failed to notice water trickling into the bilge from a freeze damaged bowl.
• Stuffing Box: On powerboats or sailboats with inboard power, if the stuffing box’s packing material that seals the prop shaft is not tight, a steady drip could eventually swamp a boat if it’s ignored. Remember, the stuffing box should only leak when the prop shaft is turning. Stuffing boxes need to be inspected routinely, regardless of the season.
To learn about more causes of sinkings, or to get your own copy of the quarterly Seaworthy go to BoatUS.com/seaworthy/sinking.