The Najad 391 Sailboat
Specs & Key Performance Indicators

The Najad 391, a centre cockpit sloop, was designed by Thorwald Karlsson and built in Sweden by Najad Varvet AB.

Najad 391

Published Specification for the Najad 391

Underwater Profile: Fin keel and skeg-hung rudder

Hull Material: GRP (Fibreglass)

Length Overall: 39'9" (12.1m)

Waterline Length: 33'2" (10.1m)

Beam: 11'11" (3.6m)

Draft: 6'3" (1.9m)

Rig Type: Masthead sloop

Displacement: 22,046lb (10,000kg)

Designer: Thorwald Karlsson

Builder: Najad Varvet AB (Sweden)

Year First Built: 1995

Year Last Built: 2003

Published Design Ratios for the Najad 391

1. Sail Area/Displacement Ratio: 16.9

Less than 16 would be considered under-powered;
16 to 20 would indicate reasonably good performance;
Over 20 suggests relatively high performance.

2. Ballast/Displacement Ratio: 42.0

Under 40: less stiff, less powerful
Over 40: stiffer, more powerful

3. Displacement/Length Ratio: 270

Under 100: Ultralight
100 to 200: Light
200 to 275: Moderate
275 to 350: Heavy
Over 350: Ultraheavy

4. Comfort Ratio: 35.8

Under 20 indicates a lightweight racing boat
20 to 30 indicates a coastal cruiser
30 to 40 indicates a moderate offshore cruising boat
40 to 50 indicates a heavy offshore boat
Over 50 indicates an extremely heavy offshore boat

5. Capsize Screening Formula: 1.7

Under 2.0 (the lower the better): Better suited for ocean passages
Over 2.0: Less suited for ocean passages

Summary Analysis of the Design Ratios for the Najad 391

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1. A Sail Area/Displacement Ratio of 16.9 suggests that the Najad 391 will, in the right conditions, approach her maximum hull speed readily and satisfy the sailing performance expectations of most cruising sailors.

2. A Ballast/Displacement Ratio of 42.0 means that the Najad 391 will stand up well to her canvas in a blow, helping her to power through the waves.

3. A Displacement/Length Ratio of 270, tells us the Najad 391 is a moderate displacement cruiser, which means she'll carry all your cruising gear without it having a dramatic effect on her performance. Most of today's sailboats intended for offshore cruising fall into this displacement category.

4. Ted Brewer's Comfort Ratio of 35.8 suggests that crew comfort of a Najad 391 in a seaway is similar to what you would associate with the motion of a moderate bluewater cruising boat - a predictable and acceptable motion for most seasoned sailors.

5. The Capsize Screening Formula (CSF) of 1.7 indicates that a Najad 391 would be a safer choice of sailboat for an ocean passage than one with a CSF of more than 2.0.

The Najad 391: Key Features

The Najad 391 is a moderate displacement sailboat that is known for its excellent righting capability and is best suited as a bluewater cruising boat. The boat has a slab reefing mainsail and a deck-stepped mast. It has an aft cockpit and is intended for offshore sailing.

The Najad 391 has a comfortable and spacious interior with two dedicated sleeping cabins that can accommodate up to four people ². The boat has a forward-facing navigation station located on the port side of the saloon. The galley is located on the starboard side of the saloon and features a two-burner stove, an oven, and a refrigerator. There are two heads on board, one located in the forward cabin and the other in the aft cabin.

The Najad 391 is known for its excellent sailing performance and Swedish craftsmanship. The new improved hull, keel, and rudder design make it an improvement on the already successful 390 model. The boat has a sail area/displacement ratio of 16.9 which suggests that it will approach its maximum hull speed readily and satisfy the sailing performance expectations of most cruising sailors.

In terms of weaknesses or limitations, the Najad 391 may need help from the engine in light winds as it is not known for being a good performer in such conditions. It also has a lively less comfortable motion at sea under sail.

Overall, the Najad 391 is an excellent choice for experienced cruisers who are looking for a comfortable and spacious sailboat that can handle offshore sailing with ease. Its excellent sailing performance and Swedish craftsmanship make it an attractive option for those who are looking for a reliable platform for long-distance cruising.

Najad Varvet AB (aka Najad Yachts)

Najad Yachts is a yacht builder headquartered in Henån, Sweden. The company was founded in 1967 by Berndt Arvidsson and Thorwald Karlsson in Kungsviken, Orust, Sweden. The first model built by Najad Yachts was a 34-foot boat designed by Olle Enderlein in 1971.

Thorwald Karlsson, a marine architect, served as a designer for the company. As of 2005, the company had 160 employees and produced up to approximately 80 yachts per year. Worldwide sales include Europe, Australia, New Zealand, Turkey and the USA.

The above text was drafted by sailboat-cruising.com using GPT-4 (OpenAI’s large-scale language-generation model) as a research assistant to develop source material; we believe it to be accurate to the best of our knowledge.