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Review of Navis 33


Navis 33
Navis 33.

Basic specs.

sail specifications
The Navis 33 is a sailboat designed by the German maritime architect Fritz Hartz. The Navis 33 is built by the German yard Kunststoffwerk H. Sparr.

Looking for a new boat? Find a Navis 33 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. 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 sandwich construction 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 core material in the sandwich construction is balsa.


Interior
Floor plan
Floor plan of Navis 33.
Interior
Interior of Navis 33. Salon

The interior is like many other boats made of mahogany. Mahogany belongs to the hardwood species, known for being water-repellent and resistant to decay. It has an attractive wood grain and holds wood polish and varnish well.
The boat is equipped with one cabin, 2+2 berths, a galley, 160.0 liter fresh water capacity and toilet facility.


Rig

The Navis 33 is built 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 gennaker or a spinnaker for optimal speed.


Keel
Keel
Keel of Navis 33. Off shore

Fin keel

The Navis 33 is built with a fin keel. The fin keel is the most common keel and provides splendid manoeuvrability. The downside is that it has less directional stability than a long keel.

The boat can enter most marinas as the draft is just about 1.60 - 1.70 meter (5.25 - 5.55 ft) dependent on the load. See immersion rate below.


Engine

Navis 33 may be equipped with an inboard Nanni diesel engine at 38 hp (28 kW). The speed is 6.0 knots.

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

The fuel tank has a capacity of 156.0 liters (41 US gallons, 34 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 Navis 33 is 1.64, indicating that this boat could - if evaluated by this formula alone - be accepted to participate in ocean races.


EU classification

Navis 33 holds a CE certification:

The boat is by European Union certified as Class A. OCEAN:
Designed for extended voyages where conditions may exceed wind force 8 (Beaufort scale) and significant wave heights of 4 m and above but excluding abnormal conditions, and vessels largely self-sufficient.


Theoretical Maximum Hull Speed

What is Theoretical Maximum Hull Speed?

The theoretical maximal speed of a displacement boat of this length is 6.8 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 Navis 33 is about 158 kg/cm, alternatively 889 lbs/inch.
Meaning: if you load 158 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 889 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 Navis 33 is 37.3.

Low High 97% 0 50 100
Comparing this ratio with similar sailboats show that it is more comfortable than 97% 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 Navis 33 is 3.23.

Wide Slim 54% 0 50 100
Compared with other similar sailboats it is slimmer than 54% 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 Navis 33 is 54%.

Low High 96% 0 50 100
This ballast ratio shows a righting moment that is higher than 96% of all similar sailboat designs. A righting moment (ability to resist heeling) significantly above average.


D/L (Displacement Length Ratio)

What is Displacement Length Ratio?

The DL-ratio for Navis 33 is 381 which categorizes this boat among 'heavy cruisers'.

Heavy Light 5% 0 50 100
5% 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.


SA/D (Sail Area Displacement ratio)

What is SA/D (Sail Area Displacement ratio)?

The SA/D for Navis 33 with ISO 8666 reference sail is 12.6, with a 135% genua the SA/D is 15.2.

Low High 7% 0 50 100
The SA/D ratio indicates that it is faster than 7% of all similar sailboat designs in light wind.


Over- / underrigged

Low High 7% 0 50 100
The Navis 33 has more rig than 7% of all similar sailboats, which indicates that the boat is significantly underrigged.


Maintenance

Hull / Deck

As balsa wood is used as sandwich core material special care must be taken in relation to work that require penetration of the sandwich construction in order to to prevent water to get in contact with the balsa wood. Otherwise the balsa wood will eventually rotten and be expensive/impossible to repair.

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 27m2 (290 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

Dimensions of sail for fractional rig.

mainsail specifications headsail specifications

Are your sails worn out? You might find your next sail here: Sails for Sale



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
Mainsail halyard 28.8 m(94.5 feet)10 mm(3/8 inch)
Jib/genoa halyard28.8 m(94.5 feet)10 mm(3/8 inch)
Spinnaker halyard28.8 m(94.5 feet)10 mm(3/8 inch)
Jib sheet 9.8 m(32.2 feet)12 mm(1/2 inch)
Genoa sheet9.8 m(32.2 feet)12 mm(1/2 inch)
Mainsheet 24.6 m(80.5 feet)12 mm(1/2 inch)
Spinnaker sheet21.6 m(70.9 feet)12 mm(1/2 inch)
Cunningham3.3 m(10.8 feet)10 mm(3/8 inch)
Kickingstrap6.6 m(21.7 feet)10 mm(3/8 inch)
Clew-outhaul6.6 m(21.7 feet)10 mm(3/8 inch)

Boat owner's ideas

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.



Finally

We are always looking for new photos. If you can contribute with photos for Navis 33 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