Why Boats Sink In Springtime

And Can Wreck Your Entire Boating Season

With the return of warm weather, boaters are once again cruising America’s waterways. But, some may be in for a rude surprise when they find their boat sinks at the dock just after being put in the water.

According to the April 2007 issue of Seaworthy, the damage-avoidance newsletter from BoatU.S., spring brings its own unique challenges to preparing and maintaining a boat in seaworthy condition.

“While not widespread, sinkings at the dock this time of year are easily avoidable,” said Seaworthy Editor Bob Adriance. “However, a spring sinking can ruin a boating season since repairs may well have to wait because marinas and boatyards are very busy outfitting and launching boats.”

After combing through the BoatU.S. Marine Insurance claims files for the most common causes of springtime sinkings, Adriance has the following tips for boaters:


• Hose clamps: Winterizing an engine in the fall often requires the removal of coolant hoses. But, sometimes 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 (boat bottom).

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 poorly caulked 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, if not properly winterized, the intake sea strainer can freeze 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. Always inspect the strainer for cracks or other damage.

• 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 will slowly swamp a boat. Also remember that no stuffing box should leak when the prop shaft is not moving. Stuffing boxes need to be inspected routinely, regardless of the season.