Review of Phantom 31

Both the hull and the deck is made of fibreglass. A hull made of fibreglass requires only a minimum of maintenance during the sailing season.

The boat is equipped with one cabin, 6 berths, a galley, 120 liters (31 US gallons, 26 imperial gallons) fresh water capacity and toilet facility.

The Phantom 31 is built with a masthead rig. The sail area for the mailsail + jib is 38.4 m² (413.3 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.

The Phantom 31 has been built with different keel alternatives.

Fin keel

The Phantom 31 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 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.

DaggerBoard aka Sword

The Phantom 31 is built with a daggerboard keel. A daggerboard is a lifting keel that can be lowered and raised vertically, allowing the boat to enter shallow waters as well.

Phantom 31 can enter even shallow marinas as the draft is just about 1.10 - 1.20 meter (3.61 - 3.91 ft) dependent on the load. See immersion rate below.

The fuel tank has a capacity of 40 liters (10 US gallons, 8 imperial gallons).

The boat may be equipped with an inboard Bukh diesel engine at 20 hp (14 kW).

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.

What is Capsize Screening Formula (CSF)?

The capsize screening value for Phantom 31 is 1.81, indicating that this boat could - if evaluated by this formula alone - be accepted to participate in ocean races.

The immersion rate is defined as the weight required to sink the boat a certain level. The immersion rate for Phantom 31 is about 179 kg/cm, alternatively 1005 lbs/inch.
Meaning: if you load 179 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 1005 lbs cargo on the boat it will sink 1 inch.

What is L/B (Length Beam Ratio)?

The l/b ratio for Phantom 31 is 3.30.

Compared with other similar sailboats it is slimmer than 66% of all other designs. It seems that the designer has chosen a slightly more speedy hull design.

What is a Ballast Ratio?

The ballast ratio for Phantom 31 is 40%.

This ballast ratio is higher than 46% of all similar sailboat designs. Since the ballast ratio and the righting moment (i.e. better ability to resist heeling) is strongly correlated, a ballast ratio just below average indicates an ability to resist heeling below average.

When buying anti-fouling bottom paint, it's nice to know how much to buy. The surface of the wet bottom is about 26m² (279 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 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.

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