Cruising Sail Trim

Jul 13, 2018 | Technical

While some H28s are rigged and equipped for racing, the majority are cruising yachts and are sailed as such.

The H28 that is not equipped for racing can still be sailed well in the cruising situation and you can get enjoyment out of trimming your sails for maximum cruising performance without that much effort and the need for extra gear.


As we all know, the genoa provides most of the drive for an H28 – except downwind. For racing or cruising, we should set the genoa first then trim the main for balance.

The first thing to do is to select the right sail for the conditions and for cruising. A No. 2 genoa is a good sail, being usable to advantage in a wider wind range than the No. 1, while not losing much power in the lighter winds. The No. 1 genoa on an H28 is good – up to 14-15 knots of wind maximum as in gusts; above this, you will be over- powered and lose either speed or pointing ability. A No. 2 genoa can be carried up to 22-25 knots with reducing main area at the higher end.

The next step is to select the sheeting point with it in mind that a flat headsail may induce weatherhelm, particularly in an H28. It is a good idea to start with the sheet lead fairly well aft then move it forward slowly until the sheet angle is approximately 45 ° from the tack. With very little helm, the yacht may be steered for relatively long periods without tiring the helmsman.

As you ease the sheets more, you will find that you should move the sheet lead forward to gain more fullness in the genoa. This changes the emphasis of the lift of the genoa as the wind direction in relation to the fore and aft line changes. For sailing close- hauled, the genoa should have ‘twist’ and this is induced by sheet tension. Too much tension reduces twist, which stalls the top of the sail, and reducing the sheet tension gives too much ‘twist’, causing the top of the sail to luff.

Set your sheet lead position by luffing up slowly and watching your telltales. The windward telltales should ‘break’ evenly from top to bottom at the same time. If the top luffs before the bottom, the sail is twisted too much. Move the lead forward to pull down on the clew, increase the leech tension, which will reduce twist. If the bottom telltale luffs first, the sail needs more twist. Move the lead aft, which will ease tension on the leech, allowing the clew to rise and the sail to twist.


For the purposes of trimming the main, it is assumed that the majority of yachts do not have a traveller, which means you will not be able to flatten the main, except in a narrow wind range or get the right twist in lighter airs.

Being able to flatten the main allows you to point higher, but sometimes this can be a disadvantage as you lose speed and have more leeway. When you are cruising, you don’t really want to be bashing along pointing as high as you can – it is better to be sailing low and fast with more comfort. Hence, you sail with a reasonable curve in the leech of the main.

The twist in the main is set with sheet tension and we watch the leech for twist. Maxim: Trim the front of the headsail and the back of the main. Set twist by trimming the sheet until the leech telltales on batten ends are all flying.

The last and continuing test of mainsail trim is to measure its total power, its contribution to the boat’s angle of keel, speed through the water and pointing ability. These factors can be measured by imagining sailing upwind in a medium breeze with the main at its most powerful setting. The wind then freshens and the main needs to be depowered gradually, first by flattening the foot tension then by reefing. The general indication of overpowering is not the angle of heel. Weatherhelm and boat speed are more relevant indicators.

You will find that as the wind increases it is better to reduce the main area by reefing, as in the H28 this will reduce the weather- helm without a reduction in speed and will add to your pointing ability. This will also reduce heeling and give more comfort to your sailing.

If the main is backwinding from the genoa, i.e. the ‘slot’ is too narrow, the main sheet should be tightened or the genoa sheet eased.

An old idea is making a reappearance after having undergone some development, and this is the full-batten main. This has the advantages of longer life through not flogging, retaining good shape in light airs and improving windward performance.