Hitting Bottom: What To Do If Your Prop Hits Ground

Experienced boaters know that hitting the bottom is not a matter of “if” but “when.” We all eventually “bottom out” in our boating careers – from the skeg ‘ticking’ the sand or an all-out grounding — and odds are that it will happen during the heat of summer, when water use and evaporation are at their highest and water levels at their lowest. We need only look West to see real-time examples of seasonal low water situations at popular boating destinations in California, Arizona and Nevada.

What To Do When Your Prop Strikes Ground

When it happens, no matter how minor or what you think you might have contacted, even if it’s just skimming a sand bottom or grazing a grass bed, whenever you have reason to believe that the hull, prop or lower unit of your boat has come into contact with anything but water, you should shut the engine down and inspect it as soon as possible.

Boat Hitting Ground Bottoming Out

Above: A family onboard a Boston Whaler hits the sand in shallow water and attempts to tilt the outboard engine up to get out, resulting in water spraying into the air. Photo: Dan Armitage.

Inspect The Propeller, Skeg And Lower Unit

The first thing you should look for is obvious damage to the propeller, the skeg and the engine’s lower unit. Depending on its severity, a small “nick” or ding in a prop blade or on the skeg probably isn’t going to end your boating day, but the prop should be repaired and the engine’s lower unit inspected by a professional before the boat is used again. On the other hand, a blade bent far enough out of position to cause a vibration that you can feel at the helm should be replaced with a spare on the spot. If a spare is not available, the boat should be motored back to the dock at the slowest speed needed to maintain headway, loaded on the trailer and taken to a professional marine mechanic or “prop shop” for repairs.

A Damaged Propeller On An Outboard Engine On A Boat

Above: A damaged propeller with dents, scratches, dings and missing paint on an boat’s outboard engine. Photo: Dan Armitage.

Don’t Run With Leaking Fluids

In the event that the lower unit is cracked, regardless of whether any lubricating fluid can be seen leaking from it, the engine should not be re-started and arrangements should be made for the boat to be towed to the ramp. Cracks may not leak fluid until the engine is operating. If fluid can be seen leaking, do you best to contain it by wrapping the raised lower unit in a plastic bag or towel, leave it in the raised position, and get a tow to the ramp.

Carry A Spare Prop Onboard

Carrying a spare can save the day when only the propeller is damaged. If replacing the prop is not an option, nicks and bent blades sometimes can be temporarily “fixed” on the spot. Using vice-grips or channel lock pliers, aluminum blades can often be bent back close enough to their original position to get the boat underway and headed back to the dock without undue vibration. That’s not the case with stainless steel, which is too strong to easily bend back into shape.

Replacing A Boat Propeller On An Outboard Engine

Above: A man replaces a boat’s propeller on an outboard engine in shallow water. Photo: Dan Armitage.

How To Repair A Bent Or Damaged Propeller

I have a friend with a small fishing boat rental business who dips the face of each of his aluminum props in a bucket of fresh concrete to make an impression before installing them on his outboards. When his customers hit something substantial enough to bend the blades, he removes the misshapen prop, places it in its mold, and hammers the aluminum back into shape using the rock-hard impression as a guide.

The Bottom Line: Avoid Shallow Water

That said, the best way to dodge damaging underwater obstacles is to avoid shallow water in the first place. But when skinny water stands between you and the dock, launch ramp or fishing grounds, sometimes you just have to take your time, put someone on the bow to point out the threats, proceed at idle speed with the outdrive tilted as far out of the water as possible to maintain headway, and cross your fingers.