Technical maintenance

The spinnaker sock: how to use it

If you’ve got more than 70-80 m² (750-850 sq ft) of sail area, using a sock for your spinnaker offers undeniable comfort and safety, so it would be wrong to deprive yourself of one, even if you have plenty of crew on board.

March 3, 2023

If you’ve got more than 70-80 m² (750-850 sq ft) of sail area, using a sock for your spinnaker offers undeniable comfort and safety, so it would be wrong to deprive yourself of one, even if you have plenty of crew on board. This is all the more true as there’s no lack of space on a catamaran’s trampolines to handle one with ease.

Whatever the make of the spinnaker sock, the operation is always the same. Here are a few tips on how to make the most of this great bit of kit, developed single-handedly by non-other than the renowned French sailor, Eric Tabarly.

 

Preparation:

Don’t attempt to pack the spinnaker into the sock on board your boat. The best solution is to wait for a day with no wind, and then fully stretch the sail out along the pontoon. Fold the spinnaker lengthwise, pass a messenger line through the empty sock which you connect to the cringle at the head of the sail where you would attach the halyard, and gently slide the sail in before connecting the cringle and the top strap together.

Hoisting:

Clip the sheet, guy and halyard to all three corners of the sail as for normal hoisting. Lay the whole sock on the trampoline and check that there are no twists in the sock by checking along the length of the longitudinal stripe. Finally, check that the spinnaker sheet is slack forward of its winch, and preset the guy.

Contrary to the way a spinnaker is normally hoisted, the genoa should be furled before hoisting. On the other hand, you should stay on a broad reach, at about 150° off the wind to avoid the sock getting caught behind the spreaders.

While one crew member is hoisting at the mast, having put at least one turn on the winch, another controls the hoist and keeps hold of the line attached to the bridle on the underside of the collar.

Opening:

Before sliding the sock up, check that the halyard is tensioned on the winch with enough turns, and with no load on the clutch (which is only there to hold it). One crew member prepares to sheet in, while another pulls on the sock’s hoisting control line, sending the collar upwards. Once hoisted, sheet in, and off you go. However, the maneuver is only complete when the sock control line is cleated off at the mast (avoid cleating it in the middle of the foredeck as there is a risk of the collar getting jammed, as the spinnaker can get tangled between the furled genoa and the sock’s control line).

Dropping:

Steer a course with the wind well aft (150° off the wind). The best thing is to slacken the guy off a little before dousing the sail, especially if the spinnaker is on a bowsprit, to make it easier to take hold of the collar after lowering the sock. The crew member on the sheet eases it all the way out, and when the spinnaker has completely spilled the wind, the collar is brought down by pulling on the control line. If this requires a lot of effort, it’s usually because the sheet is not eased enough. If necessary, you can pull it up a bit and then down again.

Start by stowing the collar into the locker first, followed by the rest of the spinnaker before you have released more than one of the three lines (halyard, sheet or guy). We’ve seen socks flying free or end up with the spinnaker in the water, having slid off the deck if there’s been a sudden movement of the boat… and this is neither economical nor ecological!