Storing a Boat on Stands and Blocks: Keel Blocking, Stand Placement and Safety Chains

Look in your owner's manual or ask the builder where the boat should be supported and whether it has any special keel requirements. BoatUS notes that some boats have specific keel-support rules and that at least one builder warns against putting weight on the keel at all. Mark heavy items (inboard engines, fuel tanks, generators) and the main bulkheads on a sketch for the yard. If the yard has never handled your model, give them this information in writing.

The best blocking in the world fails on bad ground. Check that the storage spot is firm, fairly level and drains well. Puddles, soft fill, sand, fresh gravel and clay that turns to mud in spring rain are all warning signs. BoatUS warns that stand bases can sink into mud, sand or even asphalt, and that clay that seems brick-hard can loosen after heavy spring rain. In storm areas, the spot should also be well above expected storm surge.

The weight should sit on wide, thick timbers under the keel; the wider, the better the load spreads. Cinder blocks should not be used: they crack and shift, especially when the ground softens. Brownell's training (as reported by Boating Magazine) calls for at least two sets of keel support per boat. On outboard and sterndrive boats, BoatUS recommends taking weight off the transom by lowering the drive or motor onto a block. Powerboats often need extra support under inboard engines, fuel tanks and other heavy machinery.

More is better, and more again in storm country:

• BoatUS (winter storage): at least three stands per side for boats longer than 26 feet, plus extra supports under long overhangs. One BoatUS photo shows a boat that fell when a rusted stand failed; with three stands per side instead of two, it probably would have stayed up.
• Brownell (powerboats): a minimum of four stands, with about one pair for every 8 to 10 feet of boat length as a good rule.
• Hurricane season (BoatUS): three or four per side for boats under 30 feet and five or six per side for larger boats.

These are typical guidelines; your yard, stand maker or surveyor may call for more.

• Stands should sit under strong structure: the transom, bulkheads and other main structural members. A pad pressing on an unsupported panel can push the hull in.
• They should be spread as far out from the boat as practical, which resists tipping in high wind. BoatUS shows a boat that fell after its stands were bunched together near the middle of the hull.
• The pad should meet the hull squarely so the boat's weight pushes the stand straight down. A stand that meets the hull at an angle can be forced out as the load comes on.
• On deep-V hulls, Brownell notes that sailboat-style (angled) stands often fit the bow better than vertical motorboat stands.
• Sailboats: most of the weight belongs on the keel, and Brownell still considers stacked wood blocks the best support under a sailboat keel. It also recommends a stand with a V-top on the centerline toward the bow, so the boat cannot tip forward on its keel.
• Pontoons: never put a jack or stand under the motor pod, a transducer box or the thin middle of a tube. Owners who jack pontoons on the trailer usually lift under the cross-members with a wide board to spread the load, or right at the welded seams between tube sections. Ask the pontoon builder or a dealer for safe lift points before you try it.

Each stand base should rest on a plywood pad, even on pavement. A small scrap barely larger than the base does not count; the pad has to spread the load. In the BoatUS North Carolina case, a 43-foot boat fell over on a wet, windy night after one stand without plywood sank into the mud.

Stands facing each other across the boat should be chained together so they cannot slide outward. BoatUS says safety chains must be used even when the stands are aligned perfectly, and Brownell says chain must be used with sailboat stands, which have a built-in slot to hold it. In storm season, BoatUS says stands must be on plywood and chained to stop them from spreading. If you see stands without chains, ask the yard to add them.

Once the boat is blocked, stand off at each end and look along the hull and keel, or hold a straightedge against the hull near each pad. You are checking that no stand is pushing a dent into the hull. Also check that the deck is close to level so rain drains away; standing water causes stains, mildew and gelcoat crazing. Take photos of every stand from the same spots so you can compare later.

Do not tie a tarp, cover or frame to the stands or blocking. BoatUS claim files include several boats that fell after wind filled a cover tied to the stands and pulled them out one by one. Tie covers to the boat itself, support them so they cannot fill with snow or rain, and leave scuppers and drains open so water runs off the deck.

Boats settle. BoatUS recommends checking again about two weeks after blocking. Brownell's course says stands must be checked after freeze-thaw cycles, heavy rain, wind or snow and at seasonal changes. Look for:

• A gap between a pad and the hull, or a pad that has slid
• A base that has sunk, tilted or moved off its plywood
• Rust at welds or bent stand parts
• A cover that is sagging with water or snow

Report anything you find to the yard. Do not crank a stand up yourself.

If a named storm or hurricane is forecast:

• Ask the yard to add stands to the storm counts in Step 4, all on plywood and chained.
• Ask whether they can strap the boat down to anchors in the ground or to concrete. BoatUS reports good results at marinas that strapped boats to eyes set in concrete (polyester straps work better than stretchy nylon).
• Reduce windage: remove canvas, biminis and sails, and unstep the mast if the yard can do it in time.
• Remember that boats stored ashore generally fare much better than boats left in the water, even when rising water tips them off their stands.

• Tie your ladder to the boat at the top and set its feet on firm ground, never on a stand base or plywood pad.
• Do not pull or push on a stand to steady yourself.
• When you paint the bottom, the pads leave unpainted spots. Ask the yard to move pads one at a time, with an extra stand placed first, so the boat is never short of support.
• Before launch, let the yard remove the stands and blocking. Do not loosen any of them to "help".