Review of Mermaid 315
Basic specs.
Looking for a new boat? Find a Mermaid 315 or similar boat for sale
The hull is made of hand laid fibreglass while the deck is made of 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 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 6 berths, a galley, 140.0 liter fresh water capacity and toilet facility.
The Mermaid 315 is 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 Mermaid 315 has been built with different keel alternatives.
Fin keel
One option is a fin keel. A boat with a fin keel is more manoeuvrable but has less directional stability than a similar boat with a full keel.
The keel is made of iron. Many people prefer lead keel in favour of iron. The main argument is that lead is much heavier than iron and a lead keel can therefore be made smaller which again result in less wet surface, i.e. less drag. In fact iron is quite heavy, just 30% less heavy than lead, so the advantage of a lead keel is often overstated. As the surface of a fin type keel is just a fraction of the total wet surface, the difference between an iron keel and a lead keel can in reality be ignored for cruising yachts.
The boat can enter most marinas as the draft is just about 1.59 - 1.69 meter (5.22 - 5.52 ft) dependent on the load. See immersion rate below.
Fin keel
Another option is a fin keel. A boat with a fin keel is more manoeuvrable but has less directional stability than a similar boat with a full keel.
The keel is made of lead. Compared with iron, lead has the advantage of being 44% heavier, which allows a smaller keel and hence less water resistance and higher speed.
Mermaid 315 can enter most marinas as the draft is just about 1.59 - 1.69 meter (5.22 - 5.52 ft) dependent on the load. See immersion rate below.
The Mermaid 315 has been equipped with different engine alternatives.
Alternative 1:
The boat may be equipped with an inboard Bukh DV20 diesel engine at 20 hp (14 kW). The speed is 7.5 knots.
The transmission is a saildrive.
Alternative 2:
The boat may be equipped with an inboard diesel engine at 20 hp (14 kW). Calculated max speed is about 5.2 knots
The transmission is a saildrive.
The fuel tank, which is made of fibreglass, has a capacity of 70.0 liters (18 US gallons, 15 imperial gallons).
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.
What is Capsize Screening Formula (CSF)?
The capsize screening value for Mermaid 315 is 1.85, indicating that this boat could - if evaluated by this formula alone - 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 6.9 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 Mermaid 315 is about 165 kg/cm, alternatively 927 lbs/inch.
Meaning: if you load 165 kg cargo on the boat then it will sink 1 cm.
Alternatively, if you load 927 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.
What is Motion Comfort Ratio (MCR)?
The Motion Comfort Ratio for Mermaid 315 is 26.4 - 26.9.
What is L/B (Length Beam Ratio)?
The l/b ratio for Mermaid 315 is 3.02.
The ballast ratio for Mermaid 315 is 40%.
What is Displacement Length Ratio?
The DL-ratio for Mermaid 315 is 258 which categorizes this boat among 'light crusers & offshore racers'.
What is Relative Speed Performance?
The Relative Speed Performance for Mermaid 315 is 21
Maintenance
When buying anti-fouling bottom paint, it's nice to know how much to buy.
The surface of the wet bottom is about 28m2 (301 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.
| Usage | Length | Diameter | ||
| Jib sheet | 9.3 m | (30.6 feet) | 12 mm | (1/2 inch) |
| Genoa sheet | 9.3 m | (30.6 feet) | 12 mm | (1/2 inch) |
| Mainsheet | 23.4 m | (76.6 feet) | 12 mm | (1/2 inch) |
| Spinnaker sheet | 20.5 m | (67.4 feet) | 12 mm | (1/2 inch) |
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 Mermaid 315 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.