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What to Do if You Run Aground

Many groundings happen on soft bottoms, so often you can get off without help — if you move quickly and employ the right tactics.

A moment's inattention and you find yourself straying from the channel, firmly stuck in the mud. Now what?

First things first:

Weigh the Risks

Some tactics involve considerable risk. The safety of you and your crew, your skill and experience, and good seamanship are important considerations. If these are an issue, or if weather is deteriorating or darkness is falling, call for competent help. A good towing service contract, such as TowBoatUS, is invaluable. And if there's risk to life, call the U.S. Coast Guard, which isn't in the business of pulling you off the bottom but will do all it can to save lives and save you and your crew from injuries.

Don't Waste Time

If you go aground and the tide is falling, the right maneuver in the first few minutes may make the difference between easily getting off or sustaining damage.

Quickly Assess the Bottom

Much of what we tell you here won't apply to rocky bottom or reef. Determine whether you hit soft mud, hard sand, rock, or some other type of bottom. If you don't know, find out by looking at the chart or by scooping up bottom material with an anchor. Next, verify that your hull hasn't been damaged; check immediately to be sure you're not taking on water.

Silt and Sand

Any time you use the motor when aground, you may suck a lot of the silt and sand stirred up from the bottom into the raw-water side of your engine cooling system. After the fun is over, it's a good idea to pull the impeller on the raw-water pump and check it. Look for scoring on the outer, rounded edges of the impeller. Check for cracks where its blades join the hub. (To do this, you must pull the impeller out of the pump and flex the blades to the side.) Look inside the pump for abrasion of the soft (probably bronze) surfaces and the wear plate. Also watch for engine overheating. The silt will occasionally clog the heat exchangers or other passages, and you may need to clean them also.

The Status of the Tide

Is it going up or down? How far does it have to go? A rising tide is often all you need to escape. Local tide conditions may be different from those at the reporting site on VHF weather channels or on chartplotters. Check such local indicators as current, tide lines on a day beacon, and tide lines on the shore. Remember that in many areas, the current may actually be running in although the water level is still dropping, or vice versa. Check out "The Rule of Twelfths" for more information.

Assess the Weather

If you see signs of a storm coming, you have less time than you think. Consider whether the waves, wind, or current are likely to push you into deeper water or into shallower areas.

Consider the Hull Configuration

You should know how much clearance your props and rudders have above the bottom. If your props and rudders are deeper than the hull's protected area, the grounding may have already damaged them. But if you let the boat settle even more deeply into the bottom, you'll damage them for sure.

Finding Deeper Water

Don't assume it's behind you, where you just came from. In many areas, you can read water depth by color. The higher you can get on your boat to look down at the water, the better you can tell; good polarized sunglasses may help. If you don't know where deep water is, quickly sound around your boat with a weighted line marked for depths. If that doesn't help, use your dinghy and its depth finder, or carry a handheld depth sounder for this purpose.

Most of these tactics aren't applicable if you're aground on rock or reef. If you are, quickly seek professional help. Be sure that the pro is knowledgeable and understands your situation. A forced unskilled tow off the rocks or even from a soft bottom can increase boat damage and may cost you even more in penalties.

Ungrounding Tactics

Powering Off

You'll know if it's going to work soon after you begin. If you've come into the shoal gradually and at an angle, and deeper water is just to one side, you may be able to power off by using full forward with rudder hard toward the deeper water. This will work if the force of your engine can turn the bow to the side without moving forward much; many boats move forward before the bow turns off to the side, worsening the situation. This is particularly true if your rudder is hung so far aft of your prop (often true with sailboats) that the boat depends more on forward motion for rudder leverage than prop wash.


A flat, still surface may indicate that you're looking at shallow water. A strong, evenly flowing current is a possible indication of deeper water. An eddying current could mean that you're looking at shallow water, a sharp drop-off, or a bottom obstruction.

If, when you hit, you felt a lift and then a settling of your boat, you may have come over a ridge that may now lie between your stern and deep water. If there's a ridge behind you, or if, as often occurs, the boat got turned by tide or wind, reversing may have you backing into shallower water, damaging your prop and rudder. If your prop is below your keel, or if you think it's touching the bottom, you need to try something else.


Two engines may give you a better chance. If backing off, you can alternate power surges from one to the other, pulling your boat from side to side to break the suction of the muck or sand. If you have one engine, try turning the rudder back and forth to get some of the same effect.

Illustration: Powering Off Bottom with Dual Engines

If your boat has twin engines, it's sometimes possible to use each in turn to wiggle the boat free.

If deep water is to one side, reversing the engine closest to deep water and going forward on the engine inshore may spin your boat out, assuming the props are clear. Having people move from side to side and/or toward the bow may help. If you're on a sailboat and the wind direction, speed, and weather is appropriate, put up the mainsail (or another appropriate sail) to cause the boat to heel. When you heel, you break suction and draw less water; it helps also to use the motor.

Look for Cowboys

Another boat throwing a gentle slow swell may do the trick. If you've been aground for only a few minutes, you may need only an inch or so of lift. But you must know where the water is, and you must be ready with engine thrust in the right direction as the boat lifts. Your running gear must be free from the bottom.

Illustration: Gentle Swell Lift

If you're barely aground, sometimes a little lift from a gentle slow swell is all you need.

If you're on a rocky or hard bottom, don't do this. If there are naturally occurring waves when you first go aground, you may be able to use the lift of these to bump yourself out into deeper water.

Shed Weight

Emptying water tanks or having people get into a dinghy (when it's safe) also helps. Just launching your dinghy may float the boat; you sometimes only need a fraction of an inch of elevation. I once floated a fully loaded, 41-foot lead-ballasted sailboat with a full keel just by shifting my 160 pounds into the tender I was already towing behind.

Don't Drop Anchor

Dropping the hook at the bow is sometimes counterproductive. But if you're being pushed into shallower water, you may need to.

Kedging Off

Planting your anchor well out to the side with deep water and winching the rode may also help. But it's not as simple as it sounds, except for small boats, when you can easily throw out a small anchor to the appropriate side. Taking your anchor out can be difficult and has risks.

Illustration: Kedging Off

Use your dinghy to drop anchor into deeper water, then haul in the anchor chain to unground the boat.

If it's shallow enough to do this by walking, kedging probably isn't going to work anyway, and walking out from the boat is dangerous. Often people in larger boats take the anchor out to deep water in the tender. If you do decide to try it, be sure to use the right anchor for the bottom and employ an easy-to-handle anchor and rode.

The Pivot Tactic

If you haven't gotten off quickly and easily, you may decide to undertake a more extreme tactic: the pivot push. It requires excellent boat handling skills and involves risk, but it can be very effective. Risks include injury to personnel and further damage to your boat, including additional damage to the prop, the rudder, and the keel. Only try the pivot push if you can't get a towboat.

Illustration: Pivot Push

Pivot push: Using a powered dinghy, when done exactingly, can be effective.

The tactic is usually best for groundings that occur when you've run into shallow water at an angle, coming to rest with deeper water to one side rather than dead astern. In such cases, the water may be shallow astern as well as ahead, and simply powering off may not work.

Use your dinghy to push your boat's bow toward deep water. This can help to break bottom suction and position the boat so that the full thrust of the large boat's motor can be used to push it in the right direction. (A dinghy with a sharply pointed prow probably won't do.) It seldom works to "pull your boat off" with a dinghy.

Secure something over the dinghy's bow to serve as a fender and to provide traction against your hull. Possibilities include wet heavy towels, one or more life jackets, or sheets of heavy rubber inner tube. Even an inflatable with a blunt bow needs something for chafing and to improve traction.

Approach the bow of your boat slowly, on the shallow-water side; make sure it's deep enough for the dinghy. Carefully nudge the dinghy bow into the side of the grounded boat's bow far enough back from the stem so the dinghy won't slide out around the bow but far enough forward so it has leverage to pivot the grounded boat.

After you've made gentle contact, begin to rev up the dinghy motor, pushing squarely against the side of the bow of the grounded boat. It's very important, for effectiveness and for safety, to keep the bow of your dinghy squarely against the side of the bow area of the grounded boat. Pay close attention to what's happening. When the grounded boat begins to pivot, steer the dinghy so that it continues to push squarely against the side of the grounded boat, not at an angle. If you push at an angle, you'll lose the benefit of some thrust; more important, the dinghy bow may quickly slip off to the side, resulting in its capsize. (ALWAYS wear a PFD and attach the engine's cutoff switch.)

Consider whether to take other people with you in the dinghy to remove weight from the grounded boat. But this tactic can be dangerous, especially if there's wind, current, or waves. If it's rough, let them stay on the boat. This is a decision you'll have to make carefully on the spot, weighing the risks.

If the bow of the grounded boat begins to swing toward deeper water, the helmsperson will have to shift into gear and begin increasing revs at the right time. The boat should begin to move forward into deeper water. As this happens, the person in the dinghy needs to pay close attention, because, typically, the boat will at first move almost imperceptibly, then break free suddenly with a surge of boat and water. This may not be very obvious at the wheel in the grounded boat, so the dinghy operator has to be ready to stop pushing and get out of the way at the right time. (Don't tie your tender to the mothership when you use this tactic.) It's helpful for a person to stand at the bow to facilitate communications.

A strong bow thruster may help you to pivot. It depends upon the relative size and power of your thruster, how solidly stuck you are, and whether the circumstances warrant pivoting. Try it as soon as you determine that you need to pivot. If it doesn't work then, try it as soon as you remove weight from your boat. If that doesn't work, try it while the tender is attempting to push the bow around, although this may make the dinghy operation more dangerous. The thruster wash can also make it more difficult to hold the tender's bow against the side of the bow of the grounded boat.

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Tom Neale

Technical Editor, BoatUS Magazine

One of the top technical experts in the marine industry, Tom Neale, BoatUS Magazine Technical Editor, has won nine first-place awards from Boating Writers International, and is author of the magazine’s popular "Ask The Experts" column. His depth of technical knowledge comes from living aboard various boats with his family for more than 30 years, cruising far and wide, and essentially learning how to install, fix, and rebuild every system onboard himself. A lawyer by training, for most of his career Tom has been an editor and columnist at national magazines such as Cruising World, PassageMaker, and Soundings. He wrote the acclaimed memoir All In The Same Boat (McGraw Hill), as well as Chesapeake Bay Cruising Guide, Vol. 1. These days, Tom and his wife Mel enjoy cruising their 2006 Camano 41 Chez Nous with their grandchildren.