Cruising with an
Asymmetrical Spinnaker

    One of the most popular sails in a cruising sailor's inventory is the asymmetrical cruising spinnaker. It's also known by a variety of sailmaker trade names: Genmaker, Flasher, MPS, and Spanker. Unlike the conventional spinnaker, which is symmetrical on either side of its centerline, the asymmetrical spinnaker has a definite luff and leech, with the luff being the bit longer of the two. In general, the total sail area of a cruising spinnaker is about 25 percent less than that of a standard spinnaker, but it's still about twice as big as a 150 percent genoa. The apparent-wind speeds and optimum sailing angles for those different wind speeds are shown below:
A cruising spinnaker's best angles generated by
varying apparent-wind direction and strength
Apparent-wind strength       Apparent-wind direction
5 knots 55-155 degrees
10 knots 60-155 degrees
15 knots 85-155 degrees
20 knots 120-155 degrees
    While the cruising spinnaker is designed to enhance a boat's downwind performance, it also makes downwind sailing safe and easy, especially when sailing shorthanded. Because the tack of an asymmetrical remains attached to the forestay regardless of which tack the boat is on, the cruising spinnaker does not need a pole. Gybing a conventional spinnaker with a spinnaker pole requires moving the pole's outboard end from one clew to the other; this is the moment at which most spinnaker-handling problems occur. It's also what discourages many cruising sailors from using a conventional spinnaker - they don't like to handle it unless they are sailing with an experienced crew. Gybing a cruising spinnaker, much like gybing a genoa, is an easily controlled maneuver.

Spinnaker-halyard set-up

    You can hoist the sail with either a spinnaker halyard or a genoa halyard, depending on how your boat is set up. While there are different attachment procedures and sheet leads for each halyard system, the key element is the location of the block that supports the halyard.
    A spinnaker halyard is one that exits the mast above the point where the headstay is attached. The halyard passes through a free-swiveling block that allows the halyard to pull from any direction without chafing. To set the spinnaker using this type of halyard, first attach the halyard to the head ring of the sail. If your boat has a roller-furling genoa, it is best to wrap a set of parrel beads around the furled genoa and snap-shackle them to the spinnaker tack. Parrel beads are solid nylon balls with holes drilled through them, through which a wire cable passes. Stainless steel thimbles at either end of the cable are shackled to the tack. The beads will roll over the furled genoa, allowing the tack of the cruising spinnaker to be raised and lowered with ease and keeping the tack of the spinnaker near the boat's centerline.

    Next, tie the tack downhaul line to the tack ring of the spinnaker. Run the tack downhaul line through a turning block on the deck near the bow, then aft to the cockpit. Set the downhaul line so the tack will be about 5 feet above the deck the sail is hoisted. Finally, attach the spinnaker sheet to the spinnaker's clew ring, and run the line aft outside the lifelines to a turning block located on the toerail just forward of the stern pulpit. Then run the line from the turning block forward to a winch.
    Tie the sheet that is not being used, called the lazy sheet, to the clew of the spinnaker, and lead it forward in front of the headstay, then back on the other side of the boat - outside shrouds and lifelines - to another turning block positioned forward of the stern pulpit. Lead the seet to a winch.

    To hoist the spinnaker, head off to a square run. Leave the mainsail fully eased to blanket the spinnaker and keep it from filling until your are ready to trim it. Put the spinnaker bag on the leeward side just forward of the boom.
    Once the spinnaker is fully hoisted, slowly head up to your desired course and pull in the sheet until the sail is set. Be sure to take at least three turns of the spinnaker sheet around the winch.


    Ease the spinnaker sheet unti the sail collapses in front of the boat, being careful not to lose the end of the sheet. Bear away to a dead run, and pull the main to the boat's centerline. To complete the gybe, ese the mainsail onto the new gybe and head up to your new course. Trim the new sheet (the lazy sheet from the previous tack) until the sail is set correctly for the new course.

Lowering the Spinnaker

    Bear away onto a dead run, and keep the mainsail eased. Do not east the spinnaker sheet, the sail will collapse once the mainsail blankets it. If you are not using a snuffer or dousing sock, have one person ease the halyard while another lowers the spinnaker by pulling on the leech. Ideally, whoever is lowering the sail should be positioned to leeward just in front of the boom. This position will ensure the spinnaker remains blanketed by the mainsail until it is completely lowered to the deck.

Using the Genoa Halyard

    A genoa halyard exits the mast through a sheave below the point at which the headstay is attached. Because the genoa halyard is restricted in its motion, the load must pull in an essentially forward direction to avoid being chafed by the edge of the sheave box.
    Attach the genoa halyard to the head ring on the sail. Tie the tack downhaul line to the tack ring, lead it through a turning block on the deck near the bow, and run it aft to the cock;it. As with the spinnaker halyard, set up the tack downhaul so tha tack is about 5 feet above the deck when the sail is hoisted.
    Tie the spinnaker sheet to the clew ring, and lead it outside the lifelines aft to the turning block on the toerail, then forward to a winch. The lazy sheet should also be tied to the clew and led forward outside the shrouds. But with this arrangement lead the lazy sheet between the mast and forestay, not in front of the forestay as you would with the spinnaker-halyard arrangement. Run the lazy sheet aft on the other side of the boat, outside the shrouds and lifelines, to a turning block, then forward to a winch.
    Hoisting the cruising spinnaker with a genoa halyard is exactly the same as it is with the spinnaker halyard, but gybing is a bit different. Bear away to a dead run, and leave the mainsail eased out; the main will blanket the spinnaker and cause it to collapse. Pull in the lazy sheet with at least three turns on the winch. Simultaneously ease out the old sheet. This procedure, which pulls the sail through the space between the head stay and mast, is different from having the sail pass in front of the forestay during the gybe. Gybe the mainsail, and head up to your new course, trimming the sails as you come closer to the wind.

Basic Trim

    There are two basic adjustments - the height of the tack above the deck and the amount of shet trim. Good trim for a cruising spinnaker is just enough to keep the luff from curling. As a general, when you are on a close reach (with the wind at about 60 degrees apparent), the tack should be pulled down so the luff of the sail is nearly straight. On a broad reach or run (120 to 155 degrees apparent), ease the tack off - approximately 3 feet on a 35 foot boat, 4 feet on a 45 footer, and 5 feet on a 55 footer. The tack should be as high as possible but not so high that the sail starts to oscillate. Oscillation makes the sail, and the boat, unstable. On a beam reach (90 degrees apparent), set the tack height so it is between the high and low positions.
    Adjust the tack height so the middle of the luff curls first. If the upper part of the luff curls first, the tack is to high and must be lowered. If the lower part of the luff curls first, the tack is too low and must be raised.

Dousing Socks

    The purpose of the sock is to keep the spinnaker confined during both hoisting and lowering. It is a good idea to use a dousing sock if you boat is over 30 feet long. When you hoist the spinnaker, it will be inside the sock and will not fill until you are ready for it to do so. Once you are ready to set the spinnaker, raise the sock to the top of the spinnaker by pulling the sock-control line.
    When it is time to drop the spinnaker, bear away onto a square run sto the spinnaker collapses behind the mainmail. Pull the sock-control line so the sock comes down over the collapsed spinnaker. Ease the spinnaker or genoa halyard so the sock and spinnaker are on the deck.

Spinnaker Care

    Never store a wet spinnaker inside the dousing sock, as the colors may bleed. To dry the sail, hoist it in light winds and let it air-dry or spread it out on a lawn or flat surface.