The Dock Line Trap

Dock Line Lurking

Dock lines lurk on the water surface or sometimes partly submerged like a snake hiding in long grass, patiently waiting for an unsuspecting boater to drive his propeller within striking distance. Then, Kabam! Gotcha!  A line instantly cripples your propeller and traps your boat where you are least comfortable – like a snake nailing a mouse.

Why are dock lines lurking?

Sometimes, a dock line that is secured to the dock or piling, doesn’t always land on the dock surface or on the piling hook where intended, when tossed in the excitement of undocking.

Quite often during undocking, it’s an inexperienced guest who tosses your dock line, and only part of it lands where intended. Then, the wind or current pulls the rest into the water, setting the trap.

Having owned a marina and seen the goings-on at the gas dock, we often had to pull lines out of the water left behind by boaters, to eliminate this lurking threat. The last thing we wanted was preventable chaos at the gas dock.

How to avoid the trap

When returning to your dock, or approaching a gas dock, ask your crew to watch for dock lines laying in or on the water surface. Floating dock lines drift in the current and/or wind laying in wait for an unprepared boater’s propeller to grab.

When you or your crew spot one of these dock line traps, this is the time to break out the unemployed boat hook to reach it and pull it up; so that, the prop doesn’t get tangled. You don’t want your boat to become precariously hobbled part way into your docking procedure. Since a Boat Hook is intended to be used to pick things out of the water, this is one of the only times you would use a boat hook when docking. See Boat Hook Article

What if my Prop gets tangled in the Dock Line?

If you do become a victim of the lurking line, you obviously have to abort your planned docking procedure. Then, you have some options.

A sharp knife may be your only solution to free your boat, so you can manually pull your boat to the dock where you are trapped. Now what?

For outboards and sterndrives, it’s easier than inboards. Just tilt the motor/drive all the way up, then untie or cut the rope off the prop.

For inboards, you can’t do that. So, you have two choices—haul out or dive. Haul out is easiest and is straight forward, but can be expensive for a marina to do it. If you have your own trailer, limp or get towed to the ramp.

Diving involves lots of precautions. Don’t enter the water at a marina or anchorage or anywhere near an electrical source (even a generator) until it has been turned off. See articles on ESD. Then, test the water with a meter for any stray electrical current—just to be sure.

A diver can go down with a sharp knife. Usually, they secure the knife to their wrist with a length of heavy cord; so that, they can retrieve it if dropped. Ask around for the name of a professional diver.


To prevent all the problems of getting caught in the trap, watch for dock lines floating like a snake every time you approach a dock. It’ll be there when you least expect it. Better to be prepared.

Docking can be stressful enough for boaters, who have not mastered their docking procedures. Even boaters, who have mastered Doug Dawson’s Docking Techniques and can dock like a pro, need to add this one more step to their docking procedure.

Keep your eyes on the water for lurking lines!

Click Here for information on Electrical Shock Drowning (ESD)

Click Here for information on using Boat Hooks

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