Review of GK 24
Basic specs.
Designed as an IOR half tonner
Looking for a new boat? Find a GK 24 or similar boat for saleBoth the hull and the deck is made of fibreglass. 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 boat is equipped with 2 cabins, 5 berths, a galley, 23 liters (6 US gallons, 5 imperial gallons) fresh water capacity and toilet facility.
The headroom is below average
The boat has more than one rig.
One option is a masthead rig. The sail area for the mailsail + jib is 24.1 m2 (259.7 ft2). The advantage of a masthead rig is its simplicity and the fact that a given sail area - compared with a fractional rig - can be carried lower and thus with less heeling moment.
Another option is 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.
Fin keel
The GK 24 is built with 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.
The keel is made of lead. Compared with iron, lead has the advantage of being 44% heavier, which allows a smaller keel and hence less water resistance and higher speed.
GK 24 can enter most marinas as the draft is just about 1.57 - 1.67 meter (5.15 - 5.45 ft) dependent on the load. See immersion rate below.
The fuel tank has a capacity of 23 liters (6 US gallons, 5 imperial gallons).
The boat may be equipped with an inboard Kubuto diesel engine at 18 hp (13 kW). Cruise speed is 5.0 knots. Max speed is 6.0 knots.
The transmission is a shaft drive. A shaft drive will in the long run require less maintenance than other types of drive e.g. a sail drive.
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 GK 24 is 2.27, 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 5.9 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 GK 24 is about 114 kg/cm, alternatively 639 lbs/inch.
Meaning: if you load 114 kg cargo on the boat then it will sink 1 cm.
Alternatively, if you load 639 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 GK 24 is 15.4 - 16.5.
What is L/B (Length Beam Ratio)?
The l/b ratio for GK 24 is 2.56.
The ballast ratio for GK 24 is 34%.
What is Displacement Length Ratio?
The DL-ratio for GK 24 is 249 which categorizes this boat among 'light crusers & offshore racers'.
What is SA/D (Sail Area Displacement ratio)?
The SA/D for GK 24 with ISO 8666 reference sail is 15.5, with a 135% genua the SA/D is 18.6.
Maintenance
When buying anti-fouling bottom paint, it's nice to know how much to buy.
The surface of the wet bottom is about 20m2 (215 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 masthead 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.
| Masthead rig | ||||
| Usage | Length | Diameter | ||
| Mainsail halyard | 21.1 m | (69.2 feet) | 8 mm | (5/16 inch) |
| Jib/genoa halyard | 21.1 m | (69.2 feet) | 8 mm | (5/16 inch) |
| Spinnaker halyard | 21.1 m | (69.2 feet) | 8 mm | (5/16 inch) |
| Jib sheet | 7.3 m | (23.9 feet) | 10 mm | (3/8 inch) |
| Genoa sheet | 7.3 m | (23.9 feet) | 10 mm | (3/8 inch) |
| Mainsheet | 18.2 m | (59.6 feet) | 10 mm | (3/8 inch) |
| Spinnaker sheet | 16.0 m | (52.5 feet) | 10 mm | (3/8 inch) |
| Cunningham | 2.6 m | (8.5 feet) | 8 mm | (5/16 inch) |
| Kickingstrap | 5.2 m | (17.0 feet) | 8 mm | (5/16 inch) |
| Clew-outhaul | 5.2 m | (17.0 feet) | 8 mm | (5/16 inch) |
| Fractional rig | ||||
| Usage | Length | Diameter | ||
| Mainsail halyard | 24.9 m | (81.8 feet) | 8 mm | (5/16 inch) |
| Jib/genoa halyard | 24.9 m | (81.8 feet) | 8 mm | (5/16 inch) |
| Spinnaker halyard | 24.9 m | (81.8 feet) | 8 mm | (5/16 inch) |
| Jib sheet | 7.3 m | (23.9 feet) | 10 mm | (3/8 inch) |
| Genoa sheet | 7.3 m | (23.9 feet) | 10 mm | (3/8 inch) |
| Mainsheet | 18.2 m | (59.6 feet) | 10 mm | (3/8 inch) |
| Spinnaker sheet | 16.0 m | (52.5 feet) | 10 mm | (3/8 inch) |
| Cunningham | 305.0 m | (1,000.7 feet) | 8 mm | (5/16 inch) |
| Kickingstrap | 610.0 m | (2,001.3 feet) | 8 mm | (5/16 inch) |
| Clew-outhaul | 610.0 m | (2,001.3 feet) | 8 mm | (5/16 inch) |
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