PracticalBoater
Skills : Seamanship Techniques

 

Your Starring Role In
Going Aground

By Bob Adriance
Published: October/November 2012

Sometimes, does it feel like you're hitting bottom? Well, in boating, that can be more than a feeling! Here are some proven techniques to free your boat.

No matter if you've been boating 50 years or 50 minutes, whether you own a powerboat or sailboat, whether your boat draws two feet or six, or whether the tide is rising or falling; the first thought that pops into your head the instant your boat unexpectedly touches bottom is always the same: "Oh, &#@%!" If you're lucky, it's just a momentary annoyance the boat bumps and you continue safely on your way. But the boat could also be hard aground, with many hours of struggle ahead before it's freed. If you're going to get off lightly, you'll have to react quickly. A little luck won't hurt either.

Photo of a sailboat run aground being towed

Powerboats: A powerboat skipper's initial reaction should never be to push down on the throttle, either in forward or reverse, and hope for the best. The boat's engine gets its cooling water from somewhere under the boat, and if it sucks up enough mud or sand, the engine could be ruined. This could also damage or tear off the boat's running gear. Shut the engine down until you've ascertained how far the intake is from the bottom. A light displacement boat with a shoal draft can probably be walked to deeper water by the crew if they're good swimmers, wearing shoes if needed, life jackets, and if they're aware of any dangerous current or drop-off.

Check props and rudders (if you can, safely) to make sure they haven't been damaged. On most powerboats, underwater machinery is vulnerable and must be considered as you work to free the boat. Raising an outdrive or outboard slightly will reduce draft. If you decide to use the engine, check the exhaust and temperature gauge periodically to make sure it's pumping water and not sand or mud.

Sailboats: If a boat sailing upwind is to be freed quickly, the helm should be thrown over immediately, away from the shoal, and hopefully wind will heel you off. The crew should move to leeward to reduce draft and then, with a little luck, the wind will nudge the boat back to deeper water. If the boat is sailing downwind, the chances of getting free immediately are slim unless you happen to have bumped a very short shoal. The temptation will be to try and spin the boat 180 degrees so that it's heading back toward open water. This could work, but then again, it might damage the boat's rudder, especially if it's a deep, spade rudder. If the boat remains on the shoal, drop the sails immediately so that it won't be blown further aground.

If you use your engine, make sure it's pumping water. When a boat is heeled, the intake could be out of the water or, equally as serious, sucking up sand, mud, or gunk from the bottom. Check periodically to make sure water is flowing freely from the exhaust, and keep an eye on the temperature gauge.

A Few Considerations

Whether you're freed quickly or not, anytime your boat bumps bottom, check the bilge for rising water. Inspect rudder and shaft stuffing boxes, and on sailboats, the keel bolts. If the boat is leaking badly, man the pumps and call for assistance immediately. Even if the bilge seems dry initially, keep checking periodically to make certain it's still dry.

If wind and current are in danger of putting you further onto a shoal, you'll need to set an anchor to prevent the boat from going harder aground. The anchor can also be used as a kedge to free the boat (see "Techniques"). If a dinghy is available, the anchor should be hung on its stern and the line flaked in the boat so it will pay out smoothly as you row or motor. Whatever way you get the anchor set, you'll want at least 5-to-1 scope.

Next, take soundings of the surrounding bottom to learn what you're up against. Use a lead line (if you have one) or boat hook to measure water depth around the boat and, if possible, get in the dinghy and take additional soundings further away from the boat. While you're probing, find out what type of bottom the boat is stuck in. Boats aground in mud can be rocked from side to side to break the suction (see "Techniques"). Presumably deeper water is astern, and it's probably deeper to one side or the other.

Whenever you go aground, tide is an important consideration. Hopefully, the tide will be low and rising quickly. Consult the tide tables and/or jam your boat hook into the bottom next to the boat and mark the water level with tape. When the water has risen an inch or two above the tape, start working in earnest to free the boat. If it's anywhere near high tide, however, you'll have to work fast. A falling tide can leave a boat high and dry; if you can do so safely, put seat cushions, fenders, or extra life jackets between the hull and rocks to protect it from gouges. Things to check if the boat will be lying at an awkward angle include the battery, fuel vents, any points where water could enter the boat, engine-oil dipstick, and propane bottles (which should be shut off).

Techniques

Lighten the boat. If the boat is really stuck, empty water tanks; water weighs 8.3 pounds per gallon. Heavy objects (anchors, spare batteries, chubby in-laws, and so on) can be shifted to the deepwater side of the boat, or put into the dinghy temporarily. If you're anywhere near land, you may opt to use the dinghy to carry heavy gear ashore.

Rocking The Boat. Depending on the type of bottom (both the bottom of the boat and the seabed itself), rocking the boat back and forth while twisting the wheel can be effective. Start with the engine in reverse, but if the boat isn't pulling free after a few seconds, stop, as the wash from the prop can shoot silt up under the boat. Next, try going forward, rocking the wheel back and forth. Going from forward to reverse, rocking the boat, and twisting the wheel from side to side may also free the boat.

Shifting Weight. With powerboats, try moving the crew to the section of the boat that seems to be in deeper water. This may lift the section that's aground off the bottom slightly. A sailboat with a full keel and a cutaway forefoot can sometimes be refloated by moving the crew forward. Fin-keel boats are most likely to be refloated when crew weight is moved to the rail. Which rail depends on where the water is deepest; the keel should point toward deeper water. To gain another degree or two of heel, try swinging the boom out with one or two volunteers clinging to the end.

Employ The Dinghy. If you're skilled at small-boat handling and have a dinghy with a motor, use it as a tug to push against the bow from the shallow-water side to move the bow around to point to deep water. Wear a life jacket. Beware the danger of flipping should your dinghy bow slip and the dinghy lose the "square on" position of being perpendicular to the side of the bow. Helmsman, be prepared to throttle up as soon as the bow swings.

Boat Wakes. A passing boat can send up a wake that can give your efforts a momentary boost, literally. If you're not on a rocky bottom or reef, using the engine, time your bursts on the throttle with each passing lift. As noted, be sure the engine is pumping water and keep an eye on the temperature gauge.

Set A Kedge. If you've shifted weight, gunned the engine, and tried the various maneuvers, and the boat remains stuck, you've got some work to do. Setting a kedge (anchor) out in deeper water can help free the boat and will prevent it from being nudged further onto the shoal. A windlass gives a terrific mechanical advantage pulling the boat out to deeper water. However, don't overload it. On sailboats, snatch blocks can be used to lead the anchor line from the bow to your largest winch, usually at the cockpit. One proven trick involves running the halyard over to the anchor line, using the halyard winch to heel the boat. If or when the keel floats off, use the engine to work the boat out to deeper water. If you can't pull the boat off, at least try and get the bow headed back toward deeper water. You may then be able to use the kedge together with wave action, the occasional wake, and even your engine to free the boat.

Your Next Steps It's a good idea, if you're hard aground and can't free your boat quickly, to issue a securit call on your VHF to let other vessels, and the U.S. Coast Guard, know your position, and that you're dealing with a situation just in case things get more serious. Also, if any of your passengers has a medical condition, call the Coast Guard or local authorities immediately if the situation turns into an emergency.

Call BoatUS, TowBoatUS, Or Vessel Assist. If the tide has come and gone, you've tried everything, or bad weather or other adverse conditions are threatening, use your VHF or cellphone to call for commercial assistance. You can call the BoatUS National Dispatch Center 24/7 (800-391- 4869), or ask the Coast Guard to contact BoatUS on VHF. If the call is for a basic tow or soft ungrounding, a towing representative will assist you. If your boat is insured with BoatUS and the case appears to be salvage related, call our Marine Insurance Claims Office (800-937-1937); a claims adjuster will then coordinate your salvage assistance.

If you call for assistance, prepare by getting life jackets on, and keeping your crew calm and informed. If your boat is drifting in an unsafe direction, deploy your anchor and line as quickly as possible. Make sure your GPS is working and relay your exact coordinates and depth. Keep your VHF radio tuned to Channel 16 to ensure you have communication with the towboat captain while they're on their way. Make sure when a towboat arrives, you verify it's the same company you called on the radio or phone so you won't get billed for two competing companies responding. All of our TowBoatUS and Vessel Assist captains drive red boats with distinctive graphics.End of story marker



 


Are Your Backing Plates Up To The Job?

Cleats, windlasses, winches, blocks, and stanchions should all be attached to the deck with substantial backing plates. The best are stainless. If yours are aluminum, check to be sure they’re marine-grade and very thick to minimize distortion from working and from deterioration due to galvanic corrosion where stainless bolts pass through. Thickness depends on the size of your boat and the component secured, but less than 3/8-inch could easily be inadequate. Bow tow rings (bow eyes) in the stem often can’t be backed with sufficient load spreading, and the construction of the boat may not provide enough hull strength for using this as a pull point when aground.

To get pulled off the bottom, you’ll probably need to use a cleat on a hefty windlass and/or heavy-duty bow deck cleats. The more area covered by any backing plates, the better. The wider the stress is spread under the deck, the less likely there is to be a failure. It’s not uncommon in some of today’s boats to have a windlass or cleat pull out, taking a part of the deck with it. Backing plates for windlasses, bow cleats, and other high-stress areas should be as long and wide as possible under the deck. It’s theoretically best to have a stainless backing plate for all stress fittings spreading under the entire bow deck. It also may help to utilize structural support such as bulkheads or ribs by bolting turned-down edges of the plate to these, unless this would weaken that support. Inspect regularly, looking for distortion, signs of corrosion, and flexing of the deck or other structure.