Review of Diana 21
Basic specs.
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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 interior is like few other boats made in fibreglass.
The boat is equipped with one cabin and 2 berths.
Note: the boat has also been sold to be self-made/-interiored, which means that the quality of each boat may vary.
Full keel
The Diana 21 is equipped with a long keel. A full 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.
Diana 21 can enter even shallow marinas as the draft is just about 0.45 - 0.55 meter (1.48 - 1.78 ft) dependent on the load. See immersion rate below.
The boat may be equipped with an inboard Volvo Penta MD2010 diesel engine at 10 hp (7 kW).
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, which is made of stainless steel, has a capacity of 30.0 liters (7 US gallons, 6 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 Theoretical Maximum Hull Speed?
The theoretical maximal speed of a displacement boat of this length is 6.3 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 Diana 21 is about 82 kg/cm, alternatively 464 lbs/inch.
Meaning: if you load 82 kg cargo on the boat then it will sink 1 cm.
Alternatively, if you load 464 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 L/B (Length Beam Ratio)?
The l/b ratio for Diana 21 is 3.58.
Curiosities
In Denmark, you are required to have achieved a 'powerboat driving license' in order to sail a powerboat.
In this context a boat is considered a powerboat if:
Danish definition of a powerboat
Though, if you install a motor of 47 kW (63 hp), then the boat will become a powerboat, and you will need a Danish 'powerboat driving license'
Maintenance
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 Diana 21 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.