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Text by Klaus Berger
The gaff sail is rectangular and is set on its gaff using two halyards: the peak halyard and the foot halyard. Since its development several centuries ago, the gaff sail has almost completely supplanted most other types of sail, with the exception of the square-rigged sail on large sailing vessels and simpler sails such as the sprit sail and lug sail on small boats, until it was superseded by the engine on commercial vessels and by the top-set sail on yachts.
There are at least two fundamentally different types of gaff sail: the classic type and the Dutch type.
The classic type with a topsail
In a classic gaff sail, the gaff is only slightly shorter than the boom and forms an angle of 35 to 50 degrees with the masthead or the top. This gaff angle is determined by the shape of the sail: The upper or gaff leech usually forms a right angle with the diagonal between the clew and the clew point. This means that the gaff of a narrow sail, such as the mainsail of a ketch, is never as steep as that of a wide sail. However, as a sail with a high peak pulls better, this is merely a necessary evil, because a steeper gaff on a narrow sail would flap out too far.
A classic gaff-rigged sail is accompanied by a topsail, so that the ship does not become too slow in light winds. There are marked differences between the gaff rigging of British and French boat types and that of German and Scandinavian boats.
On British boats in particular, the mainsail is always set quite low, with a fairly short mast leech. A relatively large topsail is then set above this; due to its surface area alone, it forms part of the standard close-hauled rig and is anything but an insignificant light-wind auxiliary sail. In Germany and Scandinavia, on the other hand, higher gaff sails and relatively smaller topsails have always been used.
A steeper gaff, a short mast
Many yachts built at the turn of the century and up until the 1930s are fitted with a mainsail featuring a steeper gaff. This type of sail is more effective when sailing close to the wind, as the fairly steep gaff leech, together with the luff or mast leech, forms a long leading edge. These sails are always sailed without a topsail, which, given the acute angle between the gaff and the masthead, would be minuscule anyway. Compared with a high-set sail, this type of gaff sail is still somewhat more cumbersome to handle. On the other hand, the mast is quite short, so that when the mainsail is stowed, the rig has little top-heavy weight and offers little wind resistance.
On inland waterways, there is another advantage that should not be overlooked: with the short mast, you can still pass under some bridges without having to lower the mast, provided you simply lower the gaff-piek.
The Dutch bloke
The Dutch gaff sail has a fairly long mast-leech, a long foot and a very short gaff, which is sometimes curved. Occasionally, the gaff is so short that, from a distance, the sail looks like a broad topsail. Similar sails were also once carried by numerous American boat types, often in a schooner-like two-masted rig.
As the centre of gravity of this Dutch gaff sail – which is quite narrow at the top – lies quite low, it is particularly well suited to flat, unballasted vessels such as Dutch flat-bottomed boats, which have less stability than deep-draught vessels with ballast. The long mast leech provides a good leading edge, meaning that these sails pull well to windward even without a topsail – certainly better than a low-set gaff sail when flown without a topsail.
Normally, the short gaff is also rigged with a peak halyard and a foot halyard. However, particularly on smaller boats, it is also possible to make do with a single halyard, which either attaches to the gaff a short distance behind the mast or runs through several blocks distributed along the gaff.
Mast, jib and spreader gaff
Just like almost all other types of sail, the gaff sail can be used with or without a boom. The boom sail used to be commonly known as a ‘giek’ sail, whilst the boomless sail was known as a ‘sheet’ sail. The foot of the boom sail can be secured to the boom using a luff line, sliders or a groove, or it can have a loose foot, as is the case with most utility boats. This makes it easier to reef. It also allows the halyard to be hauled in to quickly relieve the sail of wind pressure.
A modern development of the traditional gaff rig is the spreader gaff rig, also known as the wishbone rig. The spreader gaff sail is set on the mainmast of a ketch using sliders and a track, just like a topsail. However, it is triangular in shape, like a high-cut jib, and is stretched at the clew by a spreader gaff, which looks almost like a boom. A gaff sheet runs from the outer nok of the spreader gaff to the mizzen mast.
With a spreader gaff sail, a stay sail – usually fitted with a boom – is set on a fixed stay running from the top of the mizzen mast to the foot of the mainmast. The advantage of this is a large sail area, as the space between the mainmast and the mizzenmast is fully utilised, unlike with a topsail. Furthermore, it is easier to handle than a gaff rig with a topsail.
One drawback is the high cost of manufacture, due to the curved shape of the spreader gaff and the complex fittings. Furthermore, problems arise that are difficult to resolve if the gaff sheet breaks and the spreader gaff becomes dislodged high up in the rig.
So much for the traditional sail shapes commonly used in our part of the world today. Of course, there are numerous other, more exotic sail shapes, such as the lateen sail or the Pacific crab-claw sail. But those are a subject for maritime archaeologists or ethnologists.
More effort, more charm, and often more quirks too: does the Gaffel rig still have any real relevance today, or does it thrive primarily on tradition and aesthetics? Share your thoughts in the comments.