Review of Møn 27

The hull is made of hand laid fibreglass while the deck is made of fibreglass. Generally, a hull made of hand laid 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.

Both the hull and the deck is a sandwich construction which improves the indoor climate. Especially when the water is colder than the air in the cabin, then the double hull insulates against cold water and reduce the condense water in the cabin.

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 2 cabins, 5 berths, a galley, 140.0 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 Møn 27 is equipped with a masthead rig. 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.

Full keel

The Møn 27 is equipped with a long keel. A full keel provide a better directional stability than a similar boat with a fin keel; on the other hand, better directional stability means also that the boat is more difficult to handle in a harbour with less space.

The keel is made of iron. Many people prefer lead keel in favour of iron. The main argument is that lead is much heavier than iron and a lead keel can therefore be made smaller which again result in less wet surface, i.e. less drag. In fact iron is quite heavy, just 30% less heavy than lead, so the advantage of a lead keel is often overstated.

Møn 27 can enter even shallow marinas as the draft is just about 1.24 - 1.34 meter (4.07 - 4.37 ft) dependent on the load. See immersion rate below.

The boat may be equipped with an inboard Bukh DV20 diesel engine at 20 hp (14 kW). The speed is 7.0 knots.

The fuel tank, which is made of stainless steel, has a capacity of 140.0 liters (36 US gallons, 30 imperial gallons).

What is Capsize Screening Formula (CSF)?

The capsize screening value for Møn 27 is 1.97, indicating that this boat could - if evaluated by this formula alone - 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 6.6 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 Møn 27 is about 142 kg/cm, alternatively 799 lbs/inch.
Meaning: if you load 142 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 799 lbs cargo on the boat it will sink 1 inch.

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for Møn 27 is 22.1.

Comparing this ratio with similar sailboats show that it is more comfortable than 66% of all similar sailboat designs. This comfort value is just above average.

What is L/B (Length Beam Ratio)?

The l/b ratio for Møn 27 is 2.76.

Compared with other similar sailboats it is more spacy than 82% of all other designs. It seems that the designer has chosen a significantly more spacy hull design.

What is a Ballast Ratio?

The ballast ratio for Møn 27 is 38%.

This ballast ratio shows a righting moment that is higher than 42% of all similar sailboat designs. A righting moment (ability to resist heeling) just below average.

What is Displacement Length Ratio?

The DL-ratio for Møn 27 is 228 which categorizes this boat among 'light crusers & offshore racers'.

54% of all similar sailboat designs are categorized as heavier. A light displacement requires less sailarea and has higher accellerations.

SA/D (Sail Area Displacement ratio)
Indicates how fast the boat is in light wind:
- Cruising Boats have ratios 10-15
- Cruiser-Racers have ratios 16-20
- Racers have ratios above 20
- High-Performance Racers have ratios above 24
Sail-area/displacement ratio (SA/D ratio): 13.72

What is Relative Speed Performance?

The Relative Speed Performance for Møn 27 is 1

The relative speed performance is 1 which means that a it is faster than 1% of all similar sailboat designs. As this boat is a motor sailer, it is expected that the performance of a motor sailer for sail alone is lower than a dedicated sailboat.

When buying anti-fouling bottom paint, it's nice to know how much to buy. The surface of the wet bottom is about 23m² (247 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.

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.

This section is reserved boat owner's modifications, improvements, etc. Here you might find (or contribute with) inspiration for your boat.

Do you have changes/improvements you would like to share? Upload a photo and describe what you have done.

We are always looking for new photos. If you can contribute with photos for Møn 27 it would be a great help.

If you have any comments to the review, improvement suggestions, or the like, feel free to contact us. Criticism helps us to improve.

[Ref 1]: ISO 8666 Small craft — Principal data.
[Ref 3]: ISO 12215-5 Small craft — Hull construction and scantlings.