Review of Opus 34

Opus 34
Opus 34 anno 1974.

Basic specs.

sail specifications
The Opus 34 is a sailboat designed by the maritime architect Odd Rembert Andersen in the early seventies. The Opus 34 is built by the Danish yard Petersen & Thuesen Yachtværft.

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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.
The hull is a double hull 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 deck is a double deck which improves the indoor climate.

The boat is equipped with 7 berths, a galley and toilet facility.

The boat 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.


The boat is typically equipped with a SAAB engine at 16.0 hp (11 kW), which gives a max speed about 4.5 knots.

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.

Stability and Safety

What is Capsize Screening Formula (CSF)?

The capsize screening value for Opus 34 is 1.89, indicating that this boat could - if evaluated by this formula alone - be accepted to participate in ocean races.

Theoretical Maximum Hull Speed

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.

Immersion rate

The immersion rate is defined as the weight required to sink the boat a certain level. The immersion rate for Opus 34 is about 155 kg/cm, alternatively 870 lbs/inch.
Meaning: if you load 155 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 870 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.

Motion Comfort Ratio

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for Opus 34 is 26.5.

Low High 54% 0 50 100
Comparing this ratio with similar sailboats show that it is more comfortable than 54% of all similar sailboat designs. This comfort value is just above average.

L/B (Length Beam Ratio)

What is L/B (Length Beam Ratio)?

The l/b ratio for Opus 34 is 3.29.

Wide Slim 58% 0 50 100
Compared with other similar sailboats it is slimmer than 58% of all other designs. It seems that the designer has chosen a slightly more speedy hull design.

D/L (Displacement Length Ratio)

What is Displacement Length Ratio?

The DL-ratio for Opus 34 is 341 which categorizes this boat among 'heavy cruisers'.

Heavy Light 14% 0 50 100
14% 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.

RSP (Relative Speed Performance)

What is Relative Speed Performance?

The Relative Speed Performance for Opus 34 is 15

Slow Fast 15% 0 50 100
The relative speed performance is 15 which means that a it is faster than 15% of all similar sailboat designs.



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.

Guiding dimensions of running rig
Jib sheet 10.4 m(34.2 feet)12 mm(1/2 inch)
Genoa sheet10.4 m(34.2 feet)12 mm(1/2 inch)
Mainsheet 26.1 m(85.5 feet)12 mm(1/2 inch)
Spinnaker sheet22.9 m(75.2 feet)12 mm(1/2 inch)

Boat owner's ideas

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

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