How do I install a bimini on a Hallberg-Rassy 39?

Fit a bimini to your Hallberg-Rassy 39 by mocking up its position over the centre cockpit, then fitting properly backed mounting feet and a frame that clears the boom, mainsheet and cockpit entrances. Inspect beneath each proposed mounting point first, as access, deck construction and concealed equipment determine whether you can secure and seal the fittings properly.

Check existing fittings and access

There is no reliable universal drilling pattern for an HR39 bimini. Existing sprayhoods, replacement booms and previous owners' alterations can change the available space. Dimensions from another boat are only a starting point.

If you already have a frame, assemble it loosely before ordering canvas or drilling holes. Look for matching deck hinges, removable pins, support struts and old mounting holes. Photograph and label the components; an awkward-looking frame may simply have its bows or braces reversed.

Check these points on your boat:

• Mounting access: check that you can reach beneath each foot to fit backing plates, washers and nuts.
• Deck condition: investigate movement, staining or damp material around old holes before reusing them.
• Cockpit access: keep both entrances, winch handles, locker lids and the route around the wheel clear.
• Sprayhood clearance: leave room for the hood to fold and its fabric to move without rubbing against the new frame.

Mock up coverage and folding

Use timber battens or plastic conduit to represent the bows, with string marking the canopy edges. Set the height for the tallest regular helmsperson wearing shoes, then check the space beneath the boom. Proper clearance may mean accepting less standing height or a shorter canopy.

Secure the boom against accidental movement while measuring, and keep hands clear of frame hinges.

Check boom clearance with the topping lift eased into its normal sailing arrangement and the mainsheet and kicker adjusted through their working range. Clearance measured with the boom lifted at anchor can disappear under sail. Include projecting fittings, reefing lines and the mainsheet's swept path.

Decide where the folded frame will rest before fixing its pivots. Swing the mock-up through its full travel, checking that the bundled canvas will not obstruct the companionway, wheel or cockpit exits. If the frame gives good shade but blocks boarding when folded, revise the design.

A removable zipped connector between sprayhood and bimini can close the rain gap. Keep it as a separate panel so you can remove it for ventilation or sailing clearance.