Review of Duncanson 25
Basic specs.
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Both the hull and the deck is made of fibreglass. Generally, a hull made of fibreglass requires only a minimum of maintenance during the sailing season. And outside the sailing season, just bottom cleaning and perhaps anti-fouling painting once a year - a few hours of work, that's all.
The interior is like most other boats made of teak. Teak has the advantage of being naturally very oily and therefore water-repellent, which is suitable on boats.
The boat is equipped with 4+2 berths, a galley, 68.0 liter fresh water capacity and toilet facility.
Note: the boat has also been sold to be self-made/-interiored, which means that the quality of each boat may vary.
The Duncanson 25 is built with a fractional rig. A fractional rig has smaller headsails which make tacking easier, which is an advantage for cruisers and racers, of course. The downside is that having the wind from behind often requires a gennaker or a spinnaker for optimal speed.
The Duncanson 25 has been built with different keel alternatives.
Fin keel
One option is a fin keel. The fin keel is the most common keel and provides splendid manoeuvrability. The downside is that it has less directional stability than a long keel.
Duncanson 25 can enter even shallow marinas as the draft is just about 1.30 - 1.40 meter (4.27 - 4.57 ft) dependent on the load. See immersion rate below.
Swing keel
Another option is a swing keel. A swing keel is a pivoting lifting keel, allowing to sail both coastal and inland waters.
The boat can enter even shallow marinas as the draft is just about 0.41 - 0.51 meter (1.35 - 1.65 ft) dependent on the load. See immersion rate below.
The fuel tank has a capacity of 91.0 liters (24 US gallons, 20 imperial gallons).
The Duncanson 25 has been equipped with different engine alternatives.
Alternative 1:
The boat may be equipped with an inboard diesel engine
Alternative 2:
An outboard motor is often used on this boat. In that case Duncanson 25 will typically require a power of 3 - 4 hp, alternatively 67 - 81 lbs thrust if you prefer an electrical motor. Electric outboards are becoming popular for sailboat owners who want clean instant power with less noise and no exhaust fumes.
Sailing characteristics
This section covers widely used rules of thumb to describe the sailing characteristics. Please note that even though the calculations are correct, the interpretation of the results might not be valid for extreme boats.
What is Capsize Screening Formula (CSF)?
The capsize screening value for Duncanson 25 is 2.10, indicating that this boat would not be accepted to participate in ocean races.
What is Theoretical Maximum Hull Speed?
The theoretical maximal speed of a displacement boat of this length is 6.4 knots. The term "Theoretical Maximum Hull Speed" is widely used even though a boat can sail faster. The term shall be interpreted as above the theoretical speed a great additional power is necessary for a small gain in speed.
The immersion rate is defined as the weight required to sink the boat a certain level.
The immersion rate for Duncanson 25 is about 110 kg/cm, alternatively 619 lbs/inch.
Meaning: if you load 110 kg cargo on the boat then it will sink 1 cm.
Alternatively, if you load 619 lbs cargo on the boat it will sink 1 inch.
Sailing statistics
This section is statistical comparison with similar boats of the same category. The basis of the following statistical computations is our unique database with more than 26,000 different boat types and 350,000 data points.
What is Motion Comfort Ratio (MCR)?
The Motion Comfort Ratio for Duncanson 25 is 14.1.
What is L/B (Length Beam Ratio)?
The l/b ratio for Duncanson 25 is 3.25.
The ballast ratio for Duncanson 25 is 45%.
What is Displacement Length Ratio?
The DL-ratio for Duncanson 25 is 130 which categorizes this boat among 'ultra light racers'.
What is SA/D (Sail Area Displacement ratio)?
The SA/D for Duncanson 25 with ISO 8666 reference sail is 18.4, with a 135% genua the SA/D is 21.8.
Maintenance
When buying anti-fouling bottom paint, it's nice to know how much to buy.
The surface of the wet bottom is about 19m2 (204 ft2).
Based on this, your favourite maritime shop can tell you the quantity you need.
Note: If you use a paint roller you will need more paint than if you use a paintbrush.
Dimensions of sail for fractional rig.
Are your sails worn out? You might find your next sail here: Sails for Sale
If you need to renew parts of your running rig and is not quite sure of the dimensions, you may find the estimates computed below useful.
| Usage | Length | Diameter | ||
| Mainsail halyard | 20.9 m | (68.7 feet) | 8 mm | (5/16 inch) |
| Jib/genoa halyard | 20.9 m | (68.7 feet) | 8 mm | (5/16 inch) |
| Spinnaker halyard | 20.9 m | (68.7 feet) | 8 mm | (5/16 inch) |
| Jib sheet | 7.8 m | (25.6 feet) | 10 mm | (3/8 inch) |
| Genoa sheet | 7.8 m | (25.6 feet) | 10 mm | (3/8 inch) |
| Mainsheet | 19.5 m | (64.0 feet) | 10 mm | (3/8 inch) |
| Spinnaker sheet | 17.2 m | (56.3 feet) | 10 mm | (3/8 inch) |
| Cunningham | 2.9 m | (9.5 feet) | 8 mm | (5/16 inch) |
| Kickingstrap | 5.8 m | (19.0 feet) | 8 mm | (5/16 inch) |
| Clew-outhaul | 5.8 m | (19.0 feet) | 8 mm | (5/16 inch) |
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