Review of Phantom 31

Phantom 31 anno 1978.

Basic specs.

The Phantom 31 is a sailboat designed by the maritime architect Heribert Streuer. The Phantom 31 is built by the German yard Genzel.

Looking for a new boat? Find a Phantom 31 or similar boat for sale

Interior

Interior of Phantom 31 anno 1978.

The boat is equipped with 6 berths.

Keel

Keel of Phantom 31 anno 1978. Das Bild vom Unterwasserschiff zeigt leider nicht die normale Kielversion, sondern die sehr selten von Genzel gebaute Kielschwertversion mit 1,1m Tiefgang bei eingezogenem Schwert.

Unknown keel type

The boat can enter most marinas as the draft is just about 1.50 - 1.60 meter (4.92 - 5.22 ft) dependent on the load. See immersion rate below.

Engine

Phantom 31 may be equipped with an inboard engine

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.

Stability and Safety

What is Capsize Screening Formula (CSF)?

The capsize screening value for Phantom 31 is 1.18, indicating that this boat could - if evaluated by this formula alone - be accepted to participate in ocean races.

Immersion rate

The immersion rate is defined as the weight required to sink the boat a certain level. The immersion rate for Phantom 31 is about 116 kg/cm, alternatively 652 lbs/inch.
Meaning: if you load 116 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 652 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.

L/B (Length Beam Ratio)

What is L/B (Length Beam Ratio)?

The l/b ratio for Phantom 31 is 5.08.

Compared with other similar sailboats it is slimmer than 100% of all other designs. It seems that the designer has chosen a significantly more speedy hull design. This type of design is also referred to as 'needle'.

SA/D (Sail Area Displacement ratio)

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): 15.33

Maintenance

Rig

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**
Usage	Length		Diameter
Jib sheet	9.4 m	(30.8 feet)	12 mm	(1/2 inch)
Genoa sheet	9.4 m	(30.8 feet)	12 mm	(1/2 inch)
Mainsheet	23.5 m	(77.1 feet)	12 mm	(1/2 inch)
Spinnaker sheet	20.7 m	(67.8 feet)	12 mm	(1/2 inch)

Boat owner's ideas

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.

Finally

We are always looking for new photos. If you can contribute with photos for Phantom 31 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.

References

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