Review of X-312

Both the hull and the deck is made of hand laid fibreglass. Generally, a hull made of hand laid 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 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 interior is like many other boats made of mahogany.
The boat is equipped with 3 cabins, 5-6 berths, a galley and toilet facility.

The boat equipped with a fractional rig. A fractional rig has smaller headsails which make tacking easier, which is an advantage for cruisers and racers, of course. The downside is that having the wind from behind often requires a genaker or a spinnaker for optimal speed.

The boat is typically equipped with an inboard Volvo Penta engine at 9.0 hp (6 kW), which gives a max speed about 4.0 knots.

The transmission is a saildrive.

The fuel tank which is made of stainless steel has a capacity of 40 liters (10 US gallons, 8 imperial gallons).

What is Capsize Screening Formula (CSF)?

The capsize screening value for X-312 is 2.01, 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 6.6 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 X-312 is about 150 kg/cm, alternatively 844 lbs/inch.
Meaning: if you load 150 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 844 lbs cargo on the boat it will sink 1 inch.

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for X-312 is 20.8.

Comparing this ratio with similar sailboats show that it is more comfortable than 34% of all similar sailboat designs. This comfort value is just below average.

What is L/B (Length Beam Ratio)?

The l/b ratio for X-312 is 3.08.

Compared with other similar sailboats it is more spacy than 54% of all other designs. It seems that the designer has chosen a slightly more spacy hull design.

What is Displacement Length Ratio?

The DL-ratio for X-312 is 224 which categorizes this boat among 'light crusers & offshore racers'.

66% 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 X-312 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.