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Review of Najad 390


Najad 390
Najad 390 anno 1994.


Basic specs.

sail specifications
The Najad 390 is a sailboat designed in the mid eighties. The Najad 390 is built by the Swedish yard Najad Varvet AB.

Looking for a new boat? Find a Najad 390 or similar boat for sale

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

Interior
The interior is like many other boats made of mahogany.
The boat is equipped with 3 cabins, 6 berths, a galley and toilet facility.

Cockpit
Cockpit
Cockpit of Najad 390.
Rig
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.

Keel
Keel
Keel of Najad 390.

The Najad 390 is equipped with a fin keel. A boat with a fin keel is more manoeuvrable but has less directional stability than a similar boat with a long 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 only enter major marinas as the draft is about 1.85 - 1.95 meter (6.07 - 6.37 ft) dependent on the load. See immersion rate below.


Engine

Najad 390 is typically equipped with an inboard Volvo Penta MD31A diesel engine at 59.0 hp (43 kW), which gives a max speed about 7.1 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 250.0 liters (66 US gallons, 54 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.

Stability and Safety

What is Capsize Screening Formula (CSF)?

The capsize screening value for Najad 390 is 1.67, indicating that this boat could - if evaluated by this formula alone - be accepted to participate in ocean races.


Theoretical Maximum Hull Speed

What is Theoretical Maximum Hull Speed?

The theoretical maximal speed of a displacement boat of this length is 7.7 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.


Immersion rate

The immersion rate is defined as the weight required to sink the boat a certain level. The immersion rate for Najad 390 is about 234 kg/cm, alternatively 1313 lbs/inch.
Meaning: if you load 234 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 1313 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.

Motion Comfort Ratio

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for Najad 390 is 36.0.

Low High 85% 0 50 100
Comparing this ratio with similar sailboats show that it is more comfortable than 85% of all similar sailboat designs. This is a comfort value significantly above average.


L/B (Length Beam Ratio)

What is L/B (Length Beam Ratio)?

The l/b ratio for Najad 390 is 3.36.

Wide Slim 58% 0 50 100
Compared with other similar sailboats it is slimmer than 58% of all other designs. It seems that the designer has chosen a slightly more speedy hull design.


Ballast Ratio

What is a Ballast Ratio?

The ballast ratio for Najad 390 is 42%.

Low High 62% 0 50 100
This ballast ratio shows a righting moment that is higher than 62% of all similar sailboat designs. A righting moment (ability to resist heeling) just above average.


D/L (Displacement Length Ratio)

What is Displacement Length Ratio?

The DL-ratio for Najad 390 is 264 which categorizes this boat among 'light crusers & offshore racers'.

Heavy Light 46% 0 50 100
46% of all similar sailboat designs are categorized as heavier. A heavy displacement combined with smaller water plane area has lower acceleration and is more comfortable.


Maintenance

Bottom Paint

When buying anti-fouling bottom paint, it's nice to know how much to buy. The surface of the wet bottom is about 40m2 (430 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.


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
UsageLengthDiameter
Jib sheet 11.8 m(38.5 feet)14 mm(0.55 inch)
Genoa sheet11.8 m(38.5 feet)14 mm(0.55 inch)
Mainsheet 29.4 m(96.4 feet)14 mm(0.55 inch)
Spinnaker sheet25.9 m(84.8 feet)14 mm(0.55 inch)

Boat owner's ideas

This section shown boat owner's changes, improvements, etc. Here you might find inspiration for your boat.

Do you have changes/improvements you would like to share? Upload a photo and describe what to look for.



Finally

We are always looking for new photos. If you can contribute with photos for Najad 390 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