In a recent article I mentioned that the price of certain specialist racing dinghies had fallen so low that it was a pity that one couldn't alter them to cruising craft. I had looked at a few but for various reasons conversion was impossible. I would not have considered the matter further except that I was browsing through Richard Creagh-Osborn's book ‘Dinghy Building’ when my attention was drawn to the lines of the International Finn dinghy which the author had included to demonstrate the features of line drawings. The sections bore a strong similarity to those that I had shown as desirable in my article from a stability point of view, quite apart from the beautifully developed lines. The extreme beam appears to be less than ideal at 4' 11" on a length of 14' 9", but the waterline beam is very little less. Possibly from being designed as a single-hander, the buoyant sections often found in racing dinghies in the form of a deep ‘chest’ which detracts from the stability is not so prominent. Perhaps the main drawback from a cruising point of view is the low freeboard - inseparable from its racing pedigree. However, if it proved successful, I intended it for day sailing in areas of semi-sheltered water like the Solent or larger east coast estuaries, not long coastal passages. Enquiries among my racing friends elicited that it was a boat for strong, able and heavy helmsmen; as one would expect of an Olympic Class. A single cat-rigged sail of 108 square feet and no extra gunwale beam, nor crew, to help one to hold it up leads to this result.

Of course one cannot reef but flattens the sail to 'depower' it, using the Cunningham hole, bendy mast and powerful centre mainsheet tackle. No kicking strap is used to hold down the boom, in fact it would not be possible to fit it; instead the mast is thickened near the deck and the boom passes through it and is pinned in place with a wedge. The unstayed mast can rotate so a normal gooseneck is not required. The sail is cut extremely full in order to give power in light airs as no other sail is carried, and in stronger winds this requires skill in the use of the sophisticated control methods. I found out that it had a reputation for being a seaworthy craft, but was unable to ascertain what characteristics affected this opinion: certainly racing in Force 7 winds is not unknown. As more recent single-handers such as the Solo, OK and Laser have become popular mainly because they are less physically demanding, used Finns have become available from as little as £200. I chased up those adverts I could find, but the boats were either too far away or were GRP. I thought that a wooden hull would be easier to modify although I now think that there would be very little more trouble in altering a plastic boat provided that it had wooden spars. I placed an advertisement in the `Wanted' column of Yachts and Yachting for a wooden Finn. Whilst waiting for replies to my advert I made provisional plans for the conversion. The rig was the most important thing to alter of course as I had no intention of struggling with that area on a 22 foot mast. I wanted the boat as a lively day sailer, quick to rig and launch and easy to handle in crowded waters. The bermudan cat yawl would appear to suit the hull and the intended purpose, rigging the mizzen with a sprit boom but keeping the existing main boom arrangement. Among other advantages of this rig are are the following:

1 The sail area would be lower in height giving less heeling effect, as the total would be split between two sails.

2 The centre of effort of the combined sails, if calculated correctly, remains in the same fore and aft position in respect to the hull when the mainsail is reefed. The mainsail's centre of effort moves forward as the sail is reefed but the mizzen becomes a higher proportion of the total. It is therefore not necessary to reef the mizzen to retain balance.

3 The mizzen sprit boom acts also as a kicking strap.

4 The mizzen will give the ability to balance the helm when under way. When hauled amidships it will allow the dinghy to be held head to wind whilst reefing, hauling in the anchor or pouring a cup of coffee etc.

5 With no standing rigging the masts are quick to erect and the whistling and moaning sounds of wire shrouds in a fresh wind are eliminated.

6 Short tacking is easier in restricted waters as there are no jib sheets to tend.

7 The masts can be made free to rotate. This allows simple roller furling if required.

I did not want to deprive the class of a modern boat although this would probably have been too expensive for me; so did nor even discuss prices with the first couple of replies. Finally came a reply from an owner who had bought his boat only for fun sailing. He had owned it for seventeen years and for the last eight it had hung in the roof of his barn. We agreed a price subject to view; for the boat complete including two masts, two sails and an overall cover. It was stated to be in sound original condition. I had to travel to Somerset and took my trailer; the boat was as described although filthy dirty and dated 1959. Accordingly I completed the deal.

Once I had given the boat and its equipment a thorough scrub, I was very pleased with my purchase. I cannot be certain but believe the hull to be hot moulded by Fairy Marine and completed by Burton. The hull appears sound as it is varnished inside and no serious damage can be seen. The skin thickness is ⅜" - very reassuring in a boat that I intend for creek exploration. Both masts are wooden. The original is almost circular in section. The surface was discoloured by water getting beneath the varnish. A Ratsey sail is of the same date. The second mast is Scandinavian, its sail is by Elvstrom. A beautiful example of wooden mast construction, the luff groove is reinforced with glass fibre and the section is larger across than fore and aft. This of course makes it stiffer sideways than backwards. There are seven buoyancy bags, six of which date from 1959! All are rated for 100 lbs so there is adequate buoyancy even if I decide later to add a bit of ballast, as the only metal is the aluminium centreboard. The usual transom flaps as well as drainage bungs are there and a pair of Elvstrom self-bailers.

RIG In racing Finns everybody wants as full a sail as they can handle as it has the greater power in lighter winds. It is necessary to have a bendy mast to match it in order to be able to flatten the sail sufficiently to depower it in strong winds. The eleven foot boom virtually scrapes the deck when close hauled, and the end can drag in the water if the boat is allowed to heel. This can easily lead to a capsize as it impedes the ability to luff into the wind or ease the mainsail. Even with a bendy mast the heavyweight crew still has the advantage.

My ideas began to crystallise concerning the new sail plan. A new mainsail was going to be expensive, about twice what I had already paid for the boat. The newer of the two masts that I intended for the main seemed far too whippy as it was as I intended to depower my rig in a blow by reefing. Although the mast is 4" diameter where it comes through the deck to just above the boom slot, it quickly reduces to 2½" by the time it has climbed another few feet. Before I stiffened the mast I would see how well a recut main set with a shortened mast. If I was lucky I could have the benefit of the bendy mast's ability to depower the sail, as well as the reefing system which I considered essential. I would use the existing boom with its wedge system but would modify the slot so that the aft end of the boom cocked up more to give me more reasonable head, and wave clearance. While the mainsail was being recut I intended to reduce its area by shortening the mast and boom slightly anyway. I decided that the top ten feet of the old mast would do nicely for the mizzen. I could furl the sail on it by disconnecting the sprit-boom and rotating it by hand. Now came the most difficult part - deciding on the respective sails areas of main and mizzen. I decided that the whole sail area should be reduced by about 10% as I intended if possible to keep the boat as light as it was. There is of course a relationship between the fore and aft position of the centre of lateral resistance of the hull of a sailing boat and the centre of effort of the sails. There was little I could do about the lateral resistance so the best way of ensuring that the boat will remain well balanced is to arrange that the centre of effort of the new sail plan coincides as much as possible with the old.

If anyone would like to amuse themselves by designing a new rig for their boat, a separate article in this bulletin shows how to calculate sail areas and C of E's for various sail shapes.

It is difficult to add a mizzen without moving the C of E aft thus adding weather helm. However a Finn is normally sailed to windward with the head of the mast bent aft of vertical by up to some four feet and there is the roach of the leech; so in practice the standard position of the C of E is further aft than the drawing of its sail plan shows. I drew a new sail plan in which I proposed to shorten the mast by a couple of feet, shorten the boom by about afoot and cut off the roach of the mainsail which also does away with the battens. These actions moved the C of E of the mainsail forward, the result on paper looked reasonable.

The next thing was to arrange the areas of the two sails, so that as the main is reefed the C of E of the combination stays in the same fore and aft position. My attack on the main reduced the area to about 80 square feet and I drew a mizzen with a luff of 7' 6" and a foot of 4' 2" which gave 16 square feet. I wanted the minimum area for the mizzen commensurate with its purpose, as this sail does not add as much drive as the same area in the main would. When I had completed my calculations I found that the C of E hardly moved when the main was reefed. While one has to imagine for ones calculations that the CLR remains at one position, in fact it moves fore and aft a bit depending upon the point of sailing, angle of heel etc. It is therefore foolish to fuss too much over the theory - what works in practice is the important thing. I therefore drew the new sail plan with two reefs in the main, suggesting that the main mast would possibly be a bit stiffer, and sent it off to my favourite sailmaker. He announced the project feasible quoting a price for recutting the main of about the quarter the price of a new sail. I sent him the Elvstrom sail which came back within the month. He also made me a new blood red mizzen.

SAIL HANDLING The problem with sail handling on a cat rig is that the mainmast and therefore the halyard is so far forward. On a Finn the mast centre is only 29" from the stem and emerges from a lengthy foredeck. However the wedge that is inserted in the boom slot from forward to hold the boom down is controlled by a line led aft to a cleat on the boom where the helmsman can reach it. I decided that a similar arrangement would suit the halyard. I therefore fastened a cheek block to the side of the mast level with the boom and led the halyard aft along the boom to another cleat. I did not think that it was advisable to hang the fall of the halyard in a coil on the cleat where it would swing over my head, so fastened a hook forward on the boom and took the halyard over that. When one wants to add slab reefing the leech pendants can be dealt with in the normal way, but one normally has a hook or shackle where the gooseneck is, to take the luff cringles. Fortunately the designer of the Finn had a similar problem to solve when wishing to install gear for flattening the sail in strong winds. Lines are led from either side of the cockpit to blocks at the heel of the mast and then up through bullseye fairleads through the deck. One of them controls the Cunningham hole to flatten the luff, another to flatten the foot of the sail. Suitably led these could now pull down the first and second luff cringles. When reefing one slackens the mainsheet and tightens the mizzen. The dinghy now lies almost head to wind but with the boom slightly to starboard because of the offset mizzen. The reefing lines and main halyard are on the port side of the boom so lie to hand.

OARS AND ROWING A centre mainsheet leads to a track fastened to a beam across the boat which also supports the rear of the centreboard case. One cannot use it as a thwart as the sharp alloy centreplate emerges close to it! I decided therefore to keep the existing arrangement. The result is a nice roomy cockpit with wide comfortable side decks and flat sole, but nowhere to sit if one wants to row. The answer is a loose seat stored under the rear deck. Whilst I was designing it I decided that it would be a waste of space when only used as a seat, so made it into a water resistant ditty box to hold repair gear, sandwiches etc. The rowlocks are set on blocks on the side decks situated so as not to impede sitting out. The oars stow either side of the centreboard case when not in use.

BUOYANCY In view of the age of the buoyancy bags I rang the technical advice department of their manufacturer, Crewsaver. I asked whether they thought my bags might be past their useful life but they said they didn't know. I asked how I could test my bags and they couldn't help with that either. My suggestion that I sit on them seemed to be a good idea to them so I settled for that. I sat on each in turn with all my weight of 170 lbs supported and bounced gently which I thought would give a good safety margin. All passed this test but the valves without exception leaked. I replaced the soft - and perished - flat washers with '0' rings. These were best when a tightish fit: if they were a loose fit they could not be tightened without distorting. 3/32" appeared to be a suitable thickness. The Crewsaver design including that of the valve has not changed since 1959. Those I bought last year deflate almost as readily as these old ones. Other makes seem better in this respect. However my '0' rings seem to work and I will report further on them in due course. I am quite impressed by the simple system for holding the bags in place. A strong batten is fastened with spacers in the angle between side deck and hull. The straps are taken up round this, round the bag, then tied. This holds the bag close against the hull and the underside of the deck. The pillow bag for the bow had been repaired a few times and lost pressure more readily than the others. As the only way to get at it for topping it up was to wriggle full length under the foredeck I decided to scrap it. I moved the other bags forward to compensate. I will not get such a good trim when flooded, but as racing is not intended, speedy expulsion of water when on the move is no longer required.

HULL I decided to keep the self-bailers for the time being although they were bound to leak, as I didn't know how wet the dinghy would prove to be when working to windward; or whether I intended to sleep in it. The transom bungs I also kept as the ability to wash the hull through with a hose to get rid of the salt and mud keeps the hull sweet. The transom flaps, actually two round holes with plastic funnels, I sealed over with ply panels bedded on mastic. If there was any probability of swamping during capsize after completing my modifications, my scheme was a failure; if only a possibility it could be dealt with in the usual way, with bucket and sponge. The holes were useful while I was fitting the mizzen mast step however. The four carrying handles I also kept, as pushing over soft mud was likely to be part of the craft's future life. This is why I am unwilling to fit a skeg if it can be avoided. I hope to solve the problem of anchor stowage in due course - something on the lines of Richard Hignett's self-stowing CQR is in mind.

MASTS To make the mizzen fully rotating I proposed to have a 1/2" brass or bronze pin in the base engaging with a hole in the mast step. Finn masts, even wooden ones, are of course hollow. I therefore made a 3" long wooden plug using a section of the cut end as a pattern, and glued it into the base with thickened epoxy. Whilst I was at it I filled the luff groove where it wasn't needed at the bottom, with softwood dowelling in a similar way. This last strengthened the unstayed mast from its base to above the deck level. I also glued a cap of 3/16" hardwood plywood over the base end which made an accurate start possible for the drilling required for the pin. As the mast was not fully circular in section, where it was to come through the round hole in the deck I larded it on its narrow sides with epoxy thickened with high density filler, after it set I then ground it to a better shape with a rasp, checking it with a plywood template as I worked. In order that it cannot rise out of its mast step for whatever reason, I cut a small slot in the side of the mast hole in the deck - this matches with a stud inserted in the mast just below deck level. The slot is cut in such a position that when stepping the mast, the stud will only pass down through the deck when it is at 180° from its normal alignment. It is not generally appreciated that this mast does not have to be located on the centreline of the boat. It has been proved that an offset mizzen mast has no harmful effect on the handling or sailing qualities. The advantage is that you don't have to make the tiller a funny shape to work round it. On my Finn the centre of the 2½" diameter mast at the deck level is located 2¼" forward of the exterior face of the transom and 6½" off the centre line. This gives more than adequate clearance for the tiller movement. The hole through the deck is reinforced by a pad of ½" thick hardwood. No halyard is required as the sail is permanently lashed at peak and tack. When not required it is rolled up by rotating the mast with one hand.

The base of the old mast also came in useful as my trailer does not have a mast support. I therefore cut it about three feet from the bottom. I added a couple of horns to make a saddle, screwed on a couple of eyes for shock cord, then padded the top with some scraps of carpet. It sits in the usual mast hole and supports the head of the main mast. The mizzen mast with the sail rolled round it goes inside the boat when trailing.

When I shortened the main mast I found it to be solid where sawn, so had only to plug the top of the luff groove to enable the slot for the halyard sheave to be recut. I had thought that the peg and slot of the mizzen was a brilliant original idea of mine for retaining the mast in its step until I looked at the mainmast. There was a similar slot to mine already cut in its step! I hadn't noticed its significance as neither mast had a peg in the foot. I inserted a 6 mm stainless steel stud to complete the job. This gave me some peace of mind as Finns have been known to hole their forward buoyancy if their mast comes out of its step: although I have no bow buoyancy bag in my boat, it wouldn't do much for the deck if this occurred!

BOOM The boom also had the saw taken to it. It was as well that it was of deep section, 3¼" in fact, as there was of course all the reefing gear to fix as well as the halyard and slot wedge cleats. I arranged the reefing pendants so there was no slack line hanging whether the sail was reefed or not. They passed through tunnel cleats and had stopper knots in the ends which engaged in appropriately positioned plastic lashing hooks. First and second reef pendants were colour coded to avoid confusion. The external halyard passes through two guides on the forward face of the mast to keep it aligned with the sheave when the mast bends aft.

RUDDER This was in tatty condition, needing the paint to be stripped off before rebuilding. The pintles and gudgeons didn't line up and the leading edge of the blade was badly chipped. The stainless pivot bolt was fitted with mild steel nuts. All this was seen to and I added a ¼" halfround brass strip to the edge for protection. The tiller drooped, fouling the rear deck - two hardwood spacers solved the problem together with a new bolt and wing nut for the head connectlon.

MIZZEN SPARS I had a bumkin and sprit boom to make. When I had a bumkin on a canoe yawl that I used to own, it was fastened to the deck with bolts and wing nuts. That system was neither convenient nor reliable as I always worried about losing a wing nut when removing the spar for trailing. On the Finn I have arranged for it to pass through a bracket near the transom and the forward end lodges in a blind hole in a hardwood block. It cannot slide aft as it is held by a length of line though a transverse hole cleated through a tubular jamb cleat screwed to the deck. A diagram helps to explain. With such small spars as these it is not worth losing strength by making them circular in section. They are therefore rectangular with the corners rounded using a router. Even though tapered both ways, and in the case of the bumkin changing from oblong to square through its length, they are quick and easy to make.

TESTS AND TRIALS After moving the hull into the open air I was able to step the two masts and arrange the running rigging. There was insufficient play in the boom slot for the higher boom angle of the recut mainsail so I had to plane a slight angle on the bottom of the tenon of the boom where it protruded. It would appear that the slot wedge might be unnecessary, so I decided to sail without it at first. The two luff pendants for reefing ran to old nylon tunnel cleats on the coaming. These proved useless so I replaced them with Clamcleats. It would seem that the rotation of the mast on different points of sailing would require adjustment of the luff gear but this appears unnecessary in practice.

I had to wait for the right weather as October wasn't kind. Finally I got an inshore forecast of SE F3/4, misty morning followed by drizzle. In fact the club anemometer confirmed to me that the wind varied during my sail from Force 1 gradually increasing to 3 and back to 0. The boat was as quick to rig and launch as I had expected and I cast off from the pontoon into a light air; but before doing so I checked the stability by perching on the side deck as far out as I could get. I couldn't stand as the deck sloped outwards. Anyway, I had 4" of topside remaining below the gunwale. This confirmed my reading of the lines and was absurdly gratifying! A thousand Finn sailors could already have told me this I expect. I also found that I could sit on the deck right forward by the mast without heeling the craft unduly. Very few racing dinghies will put up with this, usually tipping you in without hesitation.

As my big fear was that the reduction of sail area, although still 95 square feet, would reduce her performance too much, the light wind was welcome. The spring flood tide was at full strength flowing straight down wind. In spite of this I worked steadily up tide to windward gaining a mile or so in the hour. Only two other sailing boats were out, medium sized cruisers which struggled with the conditions but lost ground steadily in spite of having respectably sized Genoas - they gave up in the end and started their engines. I experienced a little lee helm with the mainsail only drawing. As soon as I hauled in the mizzen sheet to give the sail a little bite, this changed to mild weather helm and the boat immediately accelerated. It appeared that I had got my sums right. The wind now increased to about Force 2. I tried sailing to windward sitting on the leeward side deck. I still had 3" of freeboard. I tried heaving to by hauling the mizzen sheet in tight. Although she behaved as expected, I got the impression that a larger mizzen would be preferable but I need more tests in stronger winds before being sure. There was no tendency to hang in irons when brought head to wind in this way, as there was in the case of my canoe yawl. The Finn was only too keen to get sailing again as soon as I slackened the mizzen sheet - delightful creature. If the lee helm persists in stronger winds then I shall rake the mast aft a little as at present the adjustable step is as far aft as it can go and the mast accordingly almost upright. This would make the possibility of a larger mizzen unnecessary as well.

My other fear, that the recut sail and mast wouldn't match also proved groundless. The sail set beautifully and although I had no other craft to compare with, and no compass to check, she seemed quite close winded. The credit for this must be shared between designer and sail maker. A mainsail deliberately cut for a cat rig should always be much better in this regard than a sloop mainsail used alone. Tacking proved the doddle I expected; what a joy to get rid of the headsail and its gear! An unconsidered advantage of the centre mainsheet is that a much shorter length of rope is required and therefore less clutter in the boat. I also found that the higher boom gave me adequate headroom. The slot wedge does not seem necessary.

The self-bailers leaked a little as expected, but even a sponge was unnecessary. The seating proved comfortable and I have never been keen on the typical dinghy thwart and side benches in any case. In the conditions at the start I sat on the flat bottom boards with my back against the inclined edge of the side deck and buoyancy bags. When the wind upped to Force 3, I sat on the wide side decks with my feet under the toe straps - more for security than from necessity. When reaching I could still sit inside. At Force 4 I would expect to reef as on most cruising dinghies, so more energetic gymnastics would only be indulged in from choice. I think that 80 lbs or more of lead in two pigs by the side of the centreboard case would be a useful option if greater security were required - taking the hard work out of capsize recovery if personally one considered this a probable hazard. In the existing conditions finding choppy water was impossible, so I had to make the most of the stern waves of the few commercial craft that passed. No slamming and not a drop of spray on deck seemed impressive, but my forward speed was quite low so nothing can be read from this.

Although more extensive testing is required in stronger winds I feel that I have an amenable yet lively sailing craft that I intend to keep. Incidentally, I estimate that my Finn could be returned to racing trim within half an hour using only a screwdriver and spanner. A new mast, boom and sail would be required in order to be competitive in any case; so it would only be a case of removing the rear deck fittings and the transom port covers; not that I have the slightest intention of so doing.