Review of Sun Light 31

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

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 3 cabins, 6 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 an inboard Volvo Penta 2002 diesel engine at 18.0 hp (13 kW), which gives a max speed about 6.0 knots.

The transmission is a shaft drive. A shaft drive will in the long run require less maintenence than other types of drive e.g. a sail drive.

The fuel tank which is made of stainless steel has a capacity of 45 liters (11 US gallons, 9 imperial gallons).

What is Capsize Screening Formula (CSF)?

The capsize screening value for Sun Light 31 is 2.21, 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 6.7 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 Sun Light 31 is about 166 kg/cm, alternatively 933 lbs/inch.
Meaning: if you load 166 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 933 lbs cargo on the boat it will sink 1 inch.

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for Sun Light 31 is 17.5.

Comparing this ratio with similar sailboats show that it is more comfortable than 18% of all similar sailboat designs. This is a comfort value significantly below average.

What is L/B (Length Beam Ratio)?

The l/b ratio for Sun Light 31 is 2.83.

Compared with other similar sailboats it is more spacy than 76% of all other designs. It seems that the designer has chosen a significantly more spacy hull design.

What is Displacement Length Ratio?

The DL-ratio for Sun Light 31 is 195 which categorizes this boat among 'light racers'.

79% of all similar sailboat designs are categorized as heavier. A light displacement requires less sailarea and has higher accellerations.

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 changes, 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 Sun Light 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.