In very light airs on flat water some of the strong wind principles apply to the rig. In other words the fastest shape is a flat sail with twist. This can be achieved by pre-bending the mast at deck level with, for example, a pulling system. Certain classes which do not allow “mast pullers”, or those with deck stepped masts can use spreaders angled aft with the rig tensioned to induce pre-bend.Naturally, they must be easily moved forward again to reduce bend in stronger winds. The use of the kicking strap in the lightest of airs is not recommended to bend the mast, as this tightens the leech and may cause stalling. Its sole purpose should be to prevent the boom from rising. Care should be exercised with regard to luff tension as maximum fullness on the mainsail should be maintained 40-45 degrees aft. The sail should be pulled out to its black band on the boom. On boats which possess a centre main sheet system, the traveller carriage should be brought to windward approximately 9 inches and the mainsheet eased. This helps to ease the leech whilst maintaining excellent pointing ability. On boats with transom sheeting, only the lightest of mainsheet tensions should be employed.
The jib should be trimmed to obtain a weak leech and to help maintain the desired slot shape. Less tension should be used, which gives more luff sag to compensate for the lack of wind. This does not apply to pre-bent rigs as this straightens the mast.
Off wind the kicking strap and outhaul can be used from their upwind settings to achieve a fuller sail.
Light – Medium Winds
In these conditions a helmsman needs more power from the rig, graduating from the light wind settings. There do, however, tend to be discrepancies between the techniques involved in lumpy and smooth water sailing. In lumpy seas fuller sails and a fuller entry are required to power the boat through the chop.
A fuller entry prevents the sails stalling. The clew overhaul should be eased to increase power if needed. The mast ram, if fitted, should gradually be increased to induce fullness in the sail thus developing maximum power. This forces the mast back 1/2-3/4″ maximum, depending on the class of boat. The Cunningham is still not being used.
In smoother water the outhaul does not need to be eased and more kicking strap tension may be used for less twist (fig. 21/22).
Slightly less mast ram need be used on flat water, a slightly flatter sail entry being faster
The rig tension can be set up tighter in smoother water giving a flatter jib and jib entry. Slightly more jib leech tension can be applied because of the flatter main entry.
In heavy airs the rig has to be depowered gradually from a medium wind setting to suit the overall crew weight, using more mast bend to flatten the mainsail. The kicking strap can be used to bend the mast throughout. The mast ram, if fitted, may be gradually eased but care must be taken not to loose too much pointing ability. The boom outhaul should be tight, and the Cunningham hole used to bring the draft forward and open the leech.
Flat water the rig requires more tension in order to point and therefore more kicking strap is needed to flatten the mainsail (fig. 23).
The jib fairleads usually need to be moved further back to ease the leech, although some classes rake the mast to achieve the same result usually where the fairleads cannot be moved.
Jib halyard tension supports the mast through the spreaders so more tension means more support and vice versa. In lumpy seas less jib halyard tension than in flat water might be used, as this allows the mast to bend sideways as well as fore and aft. This provides the flexibility needed to sail in waves and helps keep the slot open. Pointing ability will suffer due to less halyard tension but dinghies, in general, cannot point so high in rough seas. The emphasis lies on footing with slightly eased sheets (fig. 24/25).