Review of Johnson 23

The boat is equipped with 4 berths.

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

The Johnson 23 is 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 gennaker or a spinnaker for optimal speed.

Unknown keel type

The keel is made of iron. Many people prefer lead keel in favour of iron. The main argument is that lead is much heavier than iron and a lead keel can therefore be made smaller which again result in less wet surface, i.e. less drag. In fact iron is quite heavy, just 30% less heavy than lead, so the advantage of a lead keel is often overstated.

Johnson 23 can enter even shallow marinas as the draft is just about 1.40 - 1.50 meter (4.59 - 4.89 ft) dependent on the load. See immersion rate below.

An outboard motor is often used on this boat. In that case the boat will typically require a power of 2 - 3 hp, alternatively 48 - 58 lbs thrust if you prefer an electrical motor. Electric outboards are becoming popular for sailboat owners who want clean instant power with less noise and no exhaust fumes.

What is Capsize Screening Formula (CSF)?

The capsize screening value for Johnson 23 is 2.44, 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 5.9 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.

The immersion rate is defined as the weight required to sink the boat a certain level. The immersion rate for Johnson 23 is about 98 kg/cm, alternatively 553 lbs/inch.
Meaning: if you load 98 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 553 lbs cargo on the boat it will sink 1 inch.

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for Johnson 23 is 11.2.

What is L/B (Length Beam Ratio)?

The l/b ratio for Johnson 23 is 2.67.

What is a Ballast Ratio?

The ballast ratio for Johnson 23 is 58%.

What is Displacement Length Ratio?

The DL-ratio for Johnson 23 is 149 which categorizes this boat among 'ultra light racers'.

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

The SA/D for Johnson 23 with ISO 8666 reference sail is 16.9, with a 135% genua the SA/D is 19.7.

What is Relative Speed Performance?

The Relative Speed Performance for Johnson 23 is 62

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.

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 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 Johnson 23 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.