Review of Kirby 36

The hull is made of fibreglass. Generally, a hull made of fibreglass requires only a minimum of maintenance during the sailing season.

The boat equipped 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 genaker or a spinnaker for optimal speed.

The Kirby 36 is equipped 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 only enter major marinas as the draft is about 2.07 - 2.17 meter (6.79 - 7.09 ft) dependent on the load. See immersion rate below.

The boat is typically equipped with an inboard Yanmar 3GMD diesel engine at 27.0 hp (20 kW), which gives a max speed about 6.6 knots.

What is Capsize Screening Formula (CSF)?

The capsize screening value for Kirby 36 is 2.10, indicating that this boat would not be accepted to participate in ocean races.

What is Theoretical Maximum Hull Speed?

The theoretical maximal speed of a displacement boat of this length is 7.4 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 Kirby 36 is about 217 kg/cm, alternatively 1216 lbs/inch.
Meaning: if you load 217 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 1216 lbs cargo on the boat it will sink 1 inch.

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for Kirby 36 is 19.4.

Comparing this ratio with similar sailboats show that it is more comfortable than 14% of all similar sailboat designs. This is a comfort value significantly below average.

What is L/B (Length Beam Ratio)?

The l/b ratio for Kirby 36 is 3.12.

Compared with other similar sailboats it is more spacy than 62% of all other designs. It seems that the designer has chosen a slightly more spacy hull design.

What is Displacement Length Ratio?

The DL-ratio for Kirby 36 is 168 which categorizes this boat among 'light racers'.

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

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

The SA/D for Kirby 36 with ISO 8666 reference sail is 23.1, with a 135% genua the SA/D is 26.2.

The SA/D ratio indicates that it is faster than 98% of all similar sailboat designs in light wind.

When buying anti-fouling bottom paint, it's nice to know how much to buy. The surface of the wet bottom is about 39m² (419 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.

Dimensions of sail for fractional rig.

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.

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.

We are always looking for new photos. If you can contribute with photos for Kirby 36 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.

[Ref 1]: ISO 8666 Small craft — Principal data.
[Ref 3]: ISO 12215-5 Small craft — Hull construction and scantlings.