Select Page

I recently had two new sails made by Sanders Sails, based in Lymington UK.  The first to arrive was the new genoa and it took me a little while to get to know it and learn how to adjust it correctly.  Here is an aide memoire for getting to know how to trim a genoa so that it will deliver the best performance.

It is easier to get to know your sails in moderate conditions, ideally in winds up to Force 4.

Step 1. Getting started

Sailing upwind in 10-14 knots of breeze, sheet the sail in until the leech is just off the shrouds. Look up to make sure the sail is not hard up against the spreaders. In lighter airs, ease the sheet a little further.

Sheet lead position determines the relative position of the leech and the foot. Here there is even tension in the foot and the leech. The sail is well set and will create maximum drive.

The sheet lead position is forward, allowing the foot to sag, which makes the sail fuller. This is ok in light airs but when the breeze increases less power will be needed.

The car is moved well back, pulling the foot tight. The leech is open and there is twist in the top of the sail, de-powering the sail.

Step 2. Check the telltales

Telltales tell you whether the wind is flowing smoothly across the luff. The aim is to have all of them, on both sides of the sail, streaming together – but it is not always easy and takes practice. Here are a few tips to help you practice:

 Your first check is to luff gently from a close-hauled course while watching the windward telltales.

If the top telltale lifts first this means the leech is too slack and the sail has too much twist. Moving the car forward along the track.

  • If the top telltale starts lifting first, the sail has too much twist, meaning the leech is too slack because the sheet lead is too far aft. Move the car forward a little along the track.
  • If the bottom telltale starts lifting first, the sail has too little twist. Move the car aft a notch or two.
  • When they all lift together, you have got it right. After that, you only need to watch the bottom one while sailing. It is a good idea to mark the track with an indelible pen in order to remember the optimum settings in light, medium and high wind strengths.

If the bottom telltale starts lifting first, the sail has too little twist – move the car aft.

Other telltale signs:

  • If the leeward telltales are lifting, you either need to ease the sheet or sail closer to the wind.
  • If the windward ones are lifting, you should sheet in or bear away.
  • In strong winds when you are beginning to get over-powered, you will probably need the windward tales lifting slightly all the time.
  • Once you have freed away from a close-hauled course, the top of the sail will tend to twist open so the telltales will no longer stream.

Step 3. Adjust the fullness

In light to moderate winds – especially in a chop – you need a relatively full sail for power. That means minimal backstay tension to induce some forestay sag and not too much halyard or sheet tension either. If you find you are not moving, try letting everything off a little.

Tightening the backstay increases forestay tension, which reduces the fullness of the sail. So, increasing forestay tension helps to improve speed and pointing ability in strong winds.

When the breeze picks up, you need less power or you will be sailing on your ear with terrible weather helm. The problem is that the extra wind pressure increases forestay sag and makes the sail fuller. So, to flatten it, tighten the backstay, increase the halyard tension and sheet in harder. You may also need to move the car back a hole to flatten the foot and de-power the top of the sail.

 Step 4. Adjust the draft position

Draft position plays a major part in determining pointing ability and ease of sailing. Moving it forward (increasing halyard tension) means you won’t point so high, but reduces the heeling force in fresh conditions. The boat will also be more forgiving to sail, especially in a chop. So, if you just can’t get those telltales to settle no matter how hard you concentrate, make the sail a little rounder in the luff by tensioning the halyard.

A slack genoa halyard results in a fuller sail with the draft further back, which will help performance in light airs. Tightening the halyard will move the draft forward, better for stronger winds.

Repairing a leaking hull-to-deck joint

If you suspect a hull-to-deck joint has failed, then being absolutely sure where the actual leak is occurring is of prime...

Jester Challenge 2022 – Sailing single handed from Plymouth UK to the Azores: Part 6 – Communications

Jester Challenge – A modern experiment in old-fashioned self-reliance, self sufficiency, and personal responsibility. This is the sixth of a 10-part post where solo sailor, Bernie Branfield, shares his first-hand account of his single-handed, 2022 Jester Challenge, from Plymouth, UK to the Azores, in his 26′ Invicta Mk2, Louisa.

Fire safety advice at sea from the Marine & Coastguard Agency

Fire safety advice for boaters Top fire safety advice at sea: 1. Fit smoke alarms, carbon monoxide and gas detectors 2. Turn...

Avoiding personal dangers at sea

In order to stay safe at sea, we need to know the risks we are facing and to be aware of any personal dangers we could possibly encounter. Here are six of the most common potential dangers individual crew members should be aware of.

Care of boat batteries

Boat batteries need to be kept properly charged, which means never allowing the batteries to discharge below 50 per cent of their total charge. As well as the batteries themselves, keeping a boat’s charging systems in good shape will also help to keep batteries topped up to a higher level of charge.

Antifouling for leisure boats – Part 1

Boats that are kept afloat can very quickly become a home for small marine organisms such as barnacles, weed and slime. Applying an antifouling paint to your hull is necessary to protect it from these micro-organisms, as a fouled hull can cause problems and will slow down a boat’s maximum speed considerably if left unchecked.

Man Overboard Drill

How to respond to crew overboard under sail • Keep the MOB in sight • Tack into the heave-to position, do not adjust the...

What boating skills should you have before you buy a yacht?

Many people dream of owning a yacht and sailing off into the blue yonder. What boating skills should you have before you buy...

Cleaning & polishing painted topsides

The gelcoat topsides of a GRP boat can be pampered and restored to their former glory relatively easily when it is ashore. Gelcoat is only a very thin outer layer of the hull, often less than 1mm thick, so you should avoid cleaning it with highly abrasive cleaners, or an-ything that could potentially damage its surface.

Medical Emergency at Sea

How to deal with a medical emergency afloat   If you are planning a boating trip, it is important to have at least one...

Boat maintenance – what does it involve?

The maintenance of a boat involves things like cleaning, varnishing, painting, polishing, antifouling, servicing the engine, servicing the seacocks, and maintaining the gas and plumbing systems. It all amounts to a fairly considerable amount of work that can’t be ignored if you are to keep your boat in a safe and good condition.

Hull inspection – the annual checks

With the boat ashore for the winter it is time to do a hull inspection - the annual checks. Are there any scratches and chips in the...

How to Avoid Collisions At Sea With The ColRegs

      Every Skipper Needs Accurate Knowledge of the IRPCS ColRegs As a responsible skipper it is every skipper’s duty to learn and apply the IRPCS...

2023 Rolex Fastnet Race – Part 3

This is our third and final article about the 2023 Rolex Fastnet Race. It is a first hand account by Simon Jollands who was one of the crew of Lancelot II, a Beneteau First 40 skippered by John Gillard.

Top Ten Tips For Learning The ColRegs Boating Rules Of The Road

Colregs Boating Rules Of The Road Skippers struggle to learn and remember the ColRegs Yachtmaster and Day Skipper course...

Boating Rules of the Road – International ColRegs

    International ColRegs Rule 7: Risk of Collision Anyone who is responsible for a vessel at sea, from the...

The VHF DSC Radio jargon buster

AIS - Automatic Identification System This system is used by shipping. It allows another vessel or coast station to use...

Antifouling for leisure boats – Part 4

Applying antifouling. Antifouling is best applied on a dry, calm day. It is best to apply the antifouling in the middle of the day to ensure the hull is dry and as warm as possible.

First Aid Afloat – fish spine injury

First Aid Afloat - Here is what to do if somebody stands on a fish spine: • Check for dangers. Is it safe for you to enter...

2023 Rolex Fastnet Race

Safe Skipper’s Simon Jollands took part in the 2023 Rolex Fastnet Race – a classic offshore sailing event. This is the first of several articles on the race and focuses on the start.

Boat engine fuel system

If engines are installed and serviced correctly then most marine engines are very reliable, but one of the most important parts of the engine to check and service is the fuel system.

Understanding marine sealants & adhesives

Sealants, adhesives and adhesive sealantsThere is a bewildering variety of sealants, adhesives and even adhesive sealants available for...

Learn ColRegs: Traffic Separation Schemes

Learn ColRegs Rule 10: Traffic Separation Schemes. (c) A vessel shall, so far as practicable, avoid crossing traffic lanes...

How a propeller works

Have a look around any boatyard and you will notice quite a variety of propellers – some have two blades, some have three and others have four or more. While most propellers are completely rigid some have blades that fold.

Jester Challenge 2022 – Sailing single handed from Plymouth UK to the Azores: Part 5 – Boat Management

Jester Challenge – A modern experiment in old-fashioned self-reliance, self sufficiency, and personal responsibility. This is the fifth of a 10-part post where solo sailor, Bernie Branfield, shares his first hand account of his single-handed, 2022 Jester Challenge, from Plymouth, UK to the Azores, in his 26′ Invicta Mk2, Louisa.