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Review of Impala 30


Impala 30
Impala 30.


Basic specs.

sail specifications
The Impala 30 is a sailboat designed by the Danish maritime architect E. Bjørn Jensen in the mid seventies. The Impala 30 is built by Otto H. Nielsen.

Looking for a new boat? Find an Impala 30 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.

Both the hull and 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

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 5-6 berths, a galley, 100.0 liter fresh water capacity and toilet facility.

Note: the boat has also been sold to be self-made/-interiored, which means that the quality of each boat may vary.


Rig

Impala 30 has more than one rig.

One option is 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.

Another option is 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

Fin keel

The Impala 30 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 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.

The boat can enter most marinas as the draft is just about 1.70 - 1.80 meter (5.58 - 5.88 ft) dependent on the load. See immersion rate below.


Engine

The boat may be equipped with an inboard Yanmar SB12G diesel engine at 12 hp (8 kW). The speed is 7.0 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, 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.

Stability and Safety

What is Capsize Screening Formula (CSF)?

The capsize screening value for Impala 30 is 2.17, indicating that this boat would not 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 6.9 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 Impala 30 is about 175 kg/cm, alternatively 983 lbs/inch.
Meaning: if you load 175 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 983 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 Impala 30 is 16.3 - 18.4.

Low High 24% 0 50 100
Comparing this ratio with similar sailboats show that it is more comfortable than 24% of all similar sailboat designs. This is a comfort value significantly below average.


L/B (Length Beam Ratio)

What is L/B (Length Beam Ratio)?

The l/b ratio for Impala 30 is 2.77.

Slim Wide 82% 0 50 100
Compared with other similar sailboats it is more spacy than 82% of all other designs. It seems that the designer has chosen a significantly more spacy hull design.


Ballast Ratio

What is a Ballast Ratio?

The ballast ratio for Impala 30 is 43%.

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 Impala 30 is 176 which categorizes this boat among 'light racers'.

Heavy Light 85% 0 50 100
85% of all similar sailboat designs are categorized as heavier. A light displacement requires less sailarea and has higher accellerations.


SA/D (Sail Area Displacement ratio)

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

The SA/D for Impala 30 with ISO 8666 reference sail is 17.1, with a 135% genua the SA/D is 20.6.

Low High 62% 0 50 100
The SA/D ratio indicates that it is faster than 62% of all similar sailboat designs in light wind.


Over- / underrigged

Low High 54% 0 50 100
The Impala 30 has more rig than 54% of all similar sailboats, which indicates that the boat is slightly overrigged.


RSP (Relative Speed Performance)

What is Relative Speed Performance?

The Relative Speed Performance for Impala 30 is 82

Slow Fast 82% 0 50 100
The relative speed performance is 82 which means that a it is faster than 82% of all similar sailboat designs.


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 30m2 (322 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 genoa specifications spinnaker 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
Fractional rig
UsageLengthDiameter
Mainsail halyard 28.3 m(92.8 feet)10 mm(3/8 inch)
Jib/genoa halyard28.3 m(92.8 feet)10 mm(3/8 inch)
Spinnaker halyard28.3 m(92.8 feet)10 mm(3/8 inch)
Jib sheet 9.0 m(29.7 feet)12 mm(1/2 inch)
Genoa sheet9.0 m(29.7 feet)12 mm(1/2 inch)
Mainsheet 22.6 m(74.1 feet)12 mm(1/2 inch)
Spinnaker sheet19.9 m(65.2 feet)12 mm(1/2 inch)
Cunningham2.9 m(9.5 feet)10 mm(3/8 inch)
Kickingstrap5.8 m(19.0 feet)10 mm(3/8 inch)
Clew-outhaul5.8 m(19.0 feet)10 mm(3/8 inch)
Masthead rig
UsageLengthDiameter
Jib sheet 9.0 m(29.7 feet)12 mm(1/2 inch)
Genoa sheet9.0 m(29.7 feet)12 mm(1/2 inch)
Mainsheet 22.6 m(74.1 feet)12 mm(1/2 inch)
Spinnaker sheet19.9 m(65.2 feet)12 mm(1/2 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 Impala 30 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