Aurora II was launched in July 1950 and, although controversy concerning cruising dinghies raged in 'Yachting Monthly' shortly afterwards, I refrained from writing up as I think that anyone writing about cruising dinghies takes on a heavy responsibility and some years development and testing are required before an article can be justified. I have cruised about 1,000 miles single handed in Aurora II and am now satisfied that, apart from small details, the design is stabilised.

I propose to describe the boat in four sections: -

1) Hull 2) Rig and Fittings 3) Performance 4) Auxiliary Equipment

HULL

1.a Construction The hull is constructed to be strong enough to satisfy the following requirements:

1.a.1 Ability to stand all strains likely to be encountered when sailing, without any leaks developing. These strains can be considerable at times because the boat carried 130 lbs of cruising gear alone and sometimes, when travelling fast, and meeting a wave, she nearly leaves the water and lands again with considerable force.

1.a.2 Ability to resist the knocking about which can occur when the boat is berthed or moored in strange harbours. The topsides are mahogany which can stand a good deal of knocking about and which does not mark as easily as spruce.

1.a.3 Resistance to underwater damage. One of the advantages of a dinghy is the ability to sail in shallow water, i.e. when entering harbours at low water or exploring right to the tops of creeks. Many harbours have entrances consisting of shingle and stones, e.g. Chichester, Bembridge and Christchurch and at times I have cut things rather fine and literally ground my way over these entrances at low states of tide. The bottom of the boat is therefore planked in wych elm which is extremely hard and strong. It is, of course, heavy but its weight is low down. In spite of the hard treatment the bottom of the boat has no scratch deeper than 1/32”. The decking is of ½” mahogany planking canvas covered supported by oak beams. It would probably be better to use plywood of the same strength as this would be lighter, thus reducing top weight, but expense considerations ruled against this. Another source of strain on the hull occurs when the boat dries out on a hard bottom so the keel is made long and flat to distribute the weight.

1. b Form and Features

The shape of the hull is a compromise between many factors involved in the requirement "to get there", For instance, one might travel in a fast boat with considerable expenditure of energy, but completing a trip before becoming tired or travel more slowly in a steady boat with less strain on the crew but taking longer on the trip, I decided that the increase in speed of a racing type boat over a heavy dinghy was not very much in heavy weather and would not justify the extra expenditure of energy involved. As the heavy dinghy can be sailed single-handed, it would with a crew of two, be capable of long non-stop trips and thus prove to be a faster type of boat for long cruises. In light weather the slowness of the heavy boat can be more than offset by an engine. I considered it essential to reduce to a minimum the possibility of capsizing so employed the large beam of 5'9" on an overall length of 13'6". Michael Lawes goes even further and his boat is 5'10" beam on a length of 12'.To further increase stability, the bottom is flat floored and the hull hard bilged. To assist keeping her dry and stability at large angles of heel the freeboard is made generous and no tumble-home is employed. Tumble-home is not necessary since water is prevented from coming over the gun'l. by the side decks.

The bow section is 'V' shaped to avoid pounding when sailing to windward in rough water but some flare is incorporated to keep the bows buoyant and avoid shipping it green. This flare combined with the beamy hull results in the bows being slightly "apple cheeked" so that some pounding does still exist but not, I believe, as badly as with other types of bow. The reserve buoyancy of the bow is very important when running hard to prevent it sinking when the stern is lifted up by a following wave, as otherwise there would be an increased tendency to broach to.

The transom is always well clear of the water and the lines aft almost match those of the bow. This is necessary because the boat is often sailed at a considerable angle of heel for reasons which will be explained later and if the run aft were very flat severe weather helm would result. The rise of the run aft appears to be halfway between a steep one, which would make following seas break and a flat run which irons them out because following seas do not seem to be affected. There would be little advantage in having a very flat run as the boat is not a planing type.

The hull has a generous area of deadwood aft and this, combined with the long keel, is essential to steady the steering of the boat when running hard. The decking is generous to keep pumping to a minimum, but the side decks are narrow enough to enable the helmsman to sit right out. Decks and bottom boards are painted with non-slip.

The centreplate is 14" steel and although normally this may not have much ballast effect, I think that it does exert a considerable righting moment at large angles of heel and thus helps to prevent a capsize. The rudder has a folding steel blade which this season will be replaced by one of firmabright as, at present, the boat is slightly stern heavy. When the boat is running before a sea the stern lifts as the crests pass beneath it. This, of course, reduces the rudder depth which, combined with the broken water, tends to prevent the rudder gripping so the blade is made very deep in order to maintain control and prevent the boat broaching to.

2) RIG & FITTINGS

For windward efficiency in which the luff of the sail does most of the work the Bermudan rig is acknowledged to be the best. Again, taking the case of heavy weather however, when the sail is close reefed the Bermudan rig leaves the unused part of its mast and rigging aloft with its attendant disadvantages of weight and windage. The Gunter rig was therefore chosen with a yard that set flush with the mast and a Bermudan shaped sail.

Fittings were the same as those described in "Dinghy Cruising" by A. G. Earl. When close reefed the rig is low and strongly supported although it is slightly less efficient area for area than the Bermudan rig due to the increased turbulence at the luff resulting from a double spar. The mainsail is vertically cut in the interests of strength and the cloth is a grade heavier than that normally employed for dinghies. It is also cut rather flat and is loose footed. By adjusting the clew outhaul the sail can be tuned to be hollow for light and flat for hard winds. The loose-footed sail also avoids the distortion in the lower part of a sail that is laced to a boom and the whole of the luff is at the same angle of incidence. The sail is lowered for reefing and reef points are employed since, although roller reefing may be easier, it is difficult to avoid wrinkles when reefing single-handed. When reefing, the boat is out of control and drifts broadside, but the amount of drift is small if the plate is left down. If there is any danger of being struck by breakers then it is safer to keep the plate up, but it is not necessary to keep her bow on the seas.

Two foresails are carried. No. 1 is set at the bowsprit and can be left set when the first reef is taken in. No. 2 foresail is set at the stem when the mainsail is close reefed. Moving the small foresail aft to the stem counteracts the forward movement of the C.L.A. resulting from close reefing the mainsail. No. 1 foresail is not fitted with hanks as I thought it would be more difficult to take in, however hanks will be fitted experimentally this season as I have found that the behaviour of the boat always gives me confidence when crawling about on the foredeck in rough weather with the helm untended. The boom is kept short to reduce the windward turning moment that a mainsail exerts on a boat on a broad reach or a run and the aft end if high up to clear the helmsman.

Extension tiller and toe-straps are fitted so that the weight of the crew can be used efficiently. The toe-straps are set well out from the centre line and are detachable. Soft pads are fitted inside the coaming to cushion the calves and combined with specially shaped side seats, enable the boat to be sat out in comfort for long periods. A metal cleat is fitted on the top of the centreboard case and the mainsheet can be led under this to reduce the strain of holding it if necessary, but more often it is used for loosely belaying the mainsheet when making the boat sail herself whilst changing clothes, etc. The centreplate is fitted with arm and handle so that it can be hoisted quickly if necessary and it can also be forced down easily to clear the centreboard case of mud and stones.

Mainsail: 64 sq. ft. Spinnaker: 38 sq. ft. No. 1 Jib: 18 sq. ft. Jib Sheet: 1 ⅛” cotton No. 2 Jib: 10 sq. ft. Main Sheet: 1 ¼” cotton Spinnaker Sheet: ¾" cotton Jib Halyard: 1" It. Hemp lightly tarred

Main Halyard: ⅜” or ½” Flex. Wire Rope (6 x 19) with 1” It. hemp tail. Shrouds and forestay: ½” Plough Steel (6 x 7)

Shroud lanyards of cod line are employed and these are soaked in linseed oil to prevent stretching. The spinnaker is home made from three sections of nylon parachute and the spinnaker boom is a 7' light bamboo pole; no guys are used.

3) PERFORMANCE

3.a Sailing

3.a.1 Tacking and reaching: In order to avoid frequently reefing when sailing single-handed, the sail area is kept moderate and this, combined with the heavy beamy hull, gives the boat a relatively poor performance in light weather especially when the wind has dropped leaving a popple. Generally speaking, however, she sails faster than tabloid cruisers in light (as well as heavy) weather. In a moderate to fresh breeze one reef is taken in when single handed and the boat is allowed to heel so that the large inherent stability helps the righting moment of the crew who sits well out from the centre line in a boat of such large beam, In these conditions the boat develops a power more like a yacht than a dinghy and waves which would tend to slow a lighter boat are thrust aside or if they hit awkwardly are broken up into spray.

When sailing full and by or reaching (plate half up) quite steep waves striking on the weather bow or broadside have surprisingly little effect on the boat's behaviour although enormous quantities of spray come aboard, most of which is caught and disposed of by the decking, but even so, pumping is required fairly frequently. I have not as yet had to sail windward in open water in winds above 20 kts. In Chichester Harbour and up the lee of the Isle of Wight I have sailed close reefed in winds of 25 kts. when other dinghies have required crews of 2 - 3 though not sailing appreciably faster. In a 30 kt. wind I sail under close-reefed mainsail only and the boat sails fairly slowly. Under these conditions she really required the small jib and a crew of two to make any speed. In general, when sailing to windward in rough weather, the strain on the crew is greatly reduced by the natural stability and sea kindliness of the boat so that a long trip is more of a pleasure than a test of endurance.

3.a.2. Broad Reaching and Running. On these points of sailing the plate is hauled right up, the long keel and deadwood aft making the steering steady, especially when running hard for, under these conditions I can leave the tiller to get something from the forward locker and get back to it before the boat appreciably alters course. The wide beam, weight and short mast all contribute to steadiness when running to such an extent that the boat can usually be gybed like a yacht and when gybing in the normal dinghy manner in a 30 kt wind and rough open water conditions there is no violent alteration of course and trim. The safety of the boat when running hard is such that even if she is allowed to broach to when gybing without the crew sitting her out she will certainly heel to a large angle, but will avoid capsizing by skidding sideways, the plate being up of course. The boat does not develop any roll whatever when running. The above claims appear rather extravagant perhaps, but the boat was designed for steadiness.

3.b Rowing.

When rowing, a detachable seat is placed on top of the centreboard case, there being no centre thwart. Rowlocks are mounted at the gun'l 2" above deck level to clear the coming. In light weather, say force 1, the boat can be easily rowed fast enough to pass most yachts and the oars being springy are a delight to handle. In a breeze, with choppy water, however, rowing becomes difficult and the oars strike the coaming when the boat rolls.

3.c Under Power

Top speed under power is about 4½ kts. but the stern tends to sink at full throttle so I normally cruise at about 3½ kts. The engine being inboard has two advantages over the outboard:

1. The propeller being tucked under the stern does not come out in rough water when under power.

2. The engine is always instantly available.

A disadvantage is the continual drag of the propeller although judging from the performance when racing this does not seem serious for when the boat is heeled the propeller comes partly out of the water. Petrol consumption is about 6 - 7 hours per gallon.

3.d At Anchor

The features which assist steadiness when running also make the boat very steady at anchor so that meals can be cooked easily and a good night's rest obtained. In gale force winds the boat tends to sheer about due to the tent being high aft, but this is not serious enough to warrant reducing the headroom. The material of the tent is best quality duck; I reproofed it last winter as a precaution against weathering but it never leaks and is now five years old. It is also draught-proof and the interior quickly warms up when a meal is cooked.

Being white canvas it admits light very freely and shows up well at night. The living conditions aboard are such that there is no feeling of being cramped.

3.e Trailing.

One of the advantages claimed for light boats is that they can be easily trailed. This presumably implies that heavy boats like mine are difficult, but I have had no trouble with my brother's 1930 motorcycle combination.

4) AUXILIARY

The engine is a J.A.P. Model 4B air-cooled 4-stroke of 185 c.c. Coupling to the prop is direct and starting is by rope and pulley. A flywheel magneto is incorporated and I had the coil impregnated with wax and covered with bakelite varnish. Starting is always first swing unless I neglect to keep the carburettor clean.

The overall dimensions are 15” high by 10” length by 11” wide and the weight is 64 lbs. It is covered with a small piece of tarpaulin and requires very little attention each year. Being mounted at the aft end of the centreboard case one has to step over it when going about, but one soon gets used to it. I think an engine is an enormous advantage in a boat of this type and its main use is for getting out of harbours against the tide. Although few people will believe me, I rarely use it when the wind fails, preferring to row if the tide is fair.