Review of Marieholm AC 20

The hull 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 Marieholm AC 20 is equipped 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 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. As the surface of a fin type keel is just a fraction of the total wet surface, the difference between an iron keel and a lead keel can in reality be ignored for cruising yachts.

The boat can enter even shallow marinas as the draft is just about 0.90 - 1.00 meter (2.95 - 3.25 ft) dependent on the load. See immersion rate below.

An outboard motor is often used on this boat. In that case the boat will typically require a power of 3 - 4 hp, alternatively 55 - 66 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.

What is Capsize Screening Formula (CSF)?

The capsize screening value for Marieholm AC 20 is 2.11, 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 5.6 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 Marieholm AC 20 is about 79 kg/cm, alternatively 447 lbs/inch.
Meaning: if you load 79 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 447 lbs cargo on the boat it will sink 1 inch.

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for Marieholm AC 20 is 16.2.

Comparing this ratio with similar sailboats show that it is more comfortable than 79% of all similar sailboat designs. This is a comfort value significantly above average.

What is L/B (Length Beam Ratio)?

The l/b ratio for Marieholm AC 20 is 2.71.

Compared with other similar sailboats it is more spacy than 50% of all other designs. It seems that the designer has chosen an average hull design.

What is a Ballast Ratio?

The ballast ratio for Marieholm AC 20 is 29%.

This ballast ratio shows a righting moment that is higher than 24% of all similar sailboat designs. A righting moment (ability to resist heeling) significantly below average.

What is Displacement Length Ratio?

The DL-ratio for Marieholm AC 20 is 233 which categorizes this boat among 'light crusers & offshore racers'.

27% of all similar sailboat designs are categorized as heavier. A heavy displacement combined with smaller water plane area has lower acceleration and is more comfortable.

What is SA/D (Sail Area Displacement ratio)?

The SA/D for Marieholm AC 20 with ISO 8666 reference sail is 12.6, with a 135% genua the SA/D is 14.4.

The SA/D ratio indicates that it is faster than 8% of all similar sailboat designs in light wind.

The Marieholm AC 20 has more rig than 73% of all similar sailboats, which indicates that the boat is slightly overrigged.

What is Relative Speed Performance?

The Relative Speed Performance for Marieholm AC 20 is 4

The relative speed performance is 4 which means that a it is faster than 4% of all similar sailboat designs.

When buying anti-fouling bottom paint, it's nice to know how much to buy. The surface of the wet bottom is about 13m² (139 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.

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.

This section shown boat owner's changes, improvements, etc. Here you might find inspiration for your boat.

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

We are always looking for new photos. If you can contribute with photos for Marieholm AC 20 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.