Spinnaker Systems

Spinnaker Rigging

Originally used only on downwind courses, the spinnaker has evolved into the asymmetric design, allowing high-performance sailing dinghies to carry a spinnaker on a beam reach.

Spinnaker rigging involves attaching the three corners to sheets rather than to a spar or stay, relying on the wind’s force to keep it in position and requires skill and practice hoisting, setting and lowering. Along with the spinnaker, a spinnaker pole, a halyard and hoisting system and sheets are needed.

Leading from each clew, the sheets run outside all the rigging, to blocks and cleats on the side decks. The windward sheet is known as the guy and when gybing, the old sheet becomes the new guy. The use of a continuous sheet system where a single piece of rope is attached each of the clews is a popular sheet system.

Spinnaker Design

Made from lightweight nylon sailcloth, spinnakers shape and set is determined by the cut of the panels and how they are sewn together. Downwind spinnakers usually are cut for a full shape, a wide midsection and broad head. Reaching spinnakers are a flatter and narrower design. Sailing dinghies require only one good all-round spinnaker, whereas yachts have several spinnakers to suit a range of conditions.

Spinnaker Pole

The spinnaker pole’s purpose is extend the spinnaker clew away from the sailing dinghy allowing the sail to set correctly and is constructed of aluminium or carbon fibre with clips at each end. The inner end clips onto a bracket at the front of the mast, while the outer end clips onto the spinnaker guy. Holding the pole vertical is an uphaul and downhaul with which the angle and the height of the outer end is altered setting the spinnaker correctly for the wind strength.

The clip fitting on each end of the pole resembles a dog leash clip, which has retractable plungers, and activated by a line running from end to end and is set with the fitting's openings uppermost. Stowing the spinnaker pole varies from being stowed in the boat or stowed in brackets fitted to the boom.

Turning Blocks

The sheet turning blocks are placed as far aft as practical on the side-decks, with a reaching hook, just aft of the shrouds on each side. The sheet leads under the reaching hook and when sailing on a broad or beam reach, it holds the guy down while keeping it clear of the crew when sitting out or trapezing.

Another spinnaker rigging system uses twinning lines instead of reaching hooks comprising of a small block with a light line attached to it.

The block runs along the spinnaker sheet while the line leads through another block, mounted on the gunwale aft of the shroud, and then into a cleat where it is adjusted. The function of the twinning line on the guy is to pull it tight holding it down by the shroud while the twinning line on the sheet is left slack.

Marking the Sheets

Setting the spinnaker can be made routine with markings on the sheets so that they can be pre-set for hoisting and gybing.

When marking these positions on the sheets, the sailing dinghy is set on land, stern-to-wind, and then the spinnaker is hoisted. With the sail set square across the bow of the sailing dinghy, without the pole and neither sheet under a reaching hook, cleat the sheets.

With a permanent marker pen, mark each sheet at the point where it passes through its cleat. When preparing to gybe the spinnaker on water, cleat each sheet at its mark and the sail will correctly set for the gybe.

In making hoisting easier, especially from a windward pouch, place another set of marks on the sheets. With the sail hoisted as before, take each of the spinnaker clews in turn to a point 1m (3ft) ahead of the forestay and pull the sheet tight and cleat then mark at the cleat. Before hoisting, cleat the guy at the mark making the pole easier to fit.

Spinnaker Handling

Spinnaker handling hoist and lowering methods vary with the design of the sailing dinghy and a good system allows these actions to be done quickly, minimizing the chance of a foul-up. Modern dinghies are fitted either with a pouch stowage system on either side of the mast or a chute system at the bow.

Spinnaker Chute Systems

Chute systems have a bell-shaped mouth set into the foredeck ahead of, or to the side of, the forestay and built into the sailing dinghy.

A fabric sock or plastic tube runs under the foredeck from the mouth of the chute and contains the spinnaker when stowed.

The advantage of a chute system is the spinnaker does not become twisted when hoisted and lowered. Chute system spinnakers are often given a silicone finish which reduces friction and sheds water rapidly, as there is a tendency for a chute to funnel water over the sail when stowed.

Using a Spinnaker Chute

Hoisting the spinnaker from the chute is done using the halyard attached to the head of the sail, running down inside the mast, then aft to a jamming cleat situated at the end of the centreboard case.

Spinnaker lowering is done using a downhaul, attached to the middle of the sail running down through the chute mouth and tube. Both the halyard and downhaul can consist of a continuous piece of rope.

Releasing the halyard and pulling on the downhaul collapses the sail and it is drawn into the chute ready to be hoisted once again. A spinnaker chute system allows the sail to be hoisted and lowered effortlessly even when on a beam reach but to be safe in strong winds, bear away to a broad reach or run before hoisting or lowering.

Packing Procedure

Importantly, the spinnaker should be packed without twists in its chute before the sailing dinghy goes afloat or else it will be difficult to set the sail. On dry land, attach the halyard, sheets and downhaul to the spinnaker then hoist the sail ensuring it is not twisted. Pull on the downhaul while lowering the spinnaker, drawing the sail into the chute until it disappears into the mouth. Then take the slack out of the halyard and the sheets and cleat them.

Spinnaker Pouches

Spininnaker pouches requires more skill than chutes with the spinnaker being stored correctly with no twists ensuring that it is hoisted easily. The pouch system has two light fabric pouches either side of the mast with the sail being stowed in the leeward pouch at the time of hoisting. When the spinnaker is stowed, the spinnaker halyard is hooked under the reaching hook keeping it tidy.

Packing the Spinnaker in a Pouch

Importantly the spinnaker should be packed correctly while the sailing dinghy is ashore and is done preferably with two persons.

• The halyard and sheets are attached to the spinnaker and then hoisted.
• As one person slowly lowers the sail, the other grasps the windward clew and gathers in the luff, steadily packing it into the pouch.
• When the luff is stowed, the rest of the spinnaker is gathered, ending up in the pouch with the head and both clews on top.
• The halyard is hooked under the reaching hook and any slack is taken out of the sheets then cleated.