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Review of Jensen 29


Jensen 29
Jensen 29 anno 1969.

Basic specs.

sail specifications
The Jensen 29 is a sailboat designed by the Danish maritime architect bureau H. A. Jensen & Co. in the mid sixties. The Jensen 29 is built by the Danish yard Teknisk Plastværk.

Looking for a new boat? Find a Jensen 29 or similar boat for sale

Hull
The hull 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.

Interior
The interior is like many other boats made of mahogany.
The boat is equipped with 4 berths, a galley and toilet facility.
The headroom is above average
Note: the boat has also been sold to be self-made/-interiored, which means that the quality of each boat may vary.

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

The Jensen 29 is equipped with a long keel. A long keel provide a better directional stability than a similar boat with a fin keel; on the other hand, better directional stability means also that the boat is more difficult to handle in a harbour with less space.

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.

Jensen 29 can enter even shallow marinas as the draft is just about 1.25 - 1.35 meter (4.10 - 4.40 ft) dependent on the load. See immersion rate below.


Engine

The boat is typically equipped with an inboard Yanmar diesel engine at 10.0 hp (7 kW), which gives a max speed about 4.9 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.


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 Jensen 29 is 1.83, 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 6.1 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 Jensen 29 is about 101 kg/cm, alternatively 566 lbs/inch.
Meaning: if you load 101 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 566 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 Jensen 29 is 20.7.

Low High 38% 0 50 100
Comparing this ratio with similar sailboats show that it is more comfortable than 38% of all similar sailboat designs. This comfort value is just below average.


L/B (Length Beam Ratio)

What is L/B (Length Beam Ratio)?

The l/b ratio for Jensen 29 is 3.79.

Wide Slim 98% 0 50 100
Compared with other similar sailboats it is slimmer than 98% of all other designs. It seems that the designer has chosen a significantly more speedy hull design. This type of design is also referred to as 'needle'.


Ballast Ratio

What is a Ballast Ratio?

The ballast ratio for Jensen 29 is 55%.

Low High 99% 0 50 100
This ballast ratio shows a righting moment that is higher than 99% 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 Jensen 29 is 233 which categorizes this boat among 'light crusers & offshore racers'.

Heavy Light 62% 0 50 100
62% of all similar sailboat designs are categorized as heavier. A light displacement requires less sailarea and has higher accellerations.


RSP (Relative Speed Performance)

What is Relative Speed Performance?

The Relative Speed Performance for Jensen 29 is 4

Slow Fast 4% 0 50 100
The relative speed performance is 4 which means that a it is faster than 4% of all similar sailboat designs.


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 17m2 (182 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 8.9 m(29.4 feet)10 mm(3/8 inch)
Genoa sheet8.9 m(29.4 feet)10 mm(3/8 inch)
Mainsheet 22.4 m(73.4 feet)10 mm(3/8 inch)
Spinnaker sheet19.7 m(64.6 feet)10 mm(3/8 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 Jensen 29 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