Review of HD 20

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.

The boat is equipped with 2 berths.

The boat can enter even shallow marinas as the draft is just about 0.44 - 0.54 meter (1.44 - 1.74 ft) dependent on the load. See immersion rate below.

An outboard motor is often used on this boat. In that case HD 20 will typically require a power of 1 - 2 hp, alternatively 27 - 32 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 HD 20 is 2.26, 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 HD 20 is about 74 kg/cm, alternatively 417 lbs/inch.
Meaning: if you load 74 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 417 lbs cargo on the boat it will sink 1 inch.

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for HD 20 is 9.3.

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.

What is L/B (Length Beam Ratio)?

The l/b ratio for HD 20 is 3.18.

Compared with other similar sailboats it is slimmer than 93% 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'.

What is Displacement Length Ratio?

The DL-ratio for HD 20 is 84 which categorizes this boat among 'ultra light racers'.

90% 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)
Indicates how fast the boat is in light wind:
- Cruising Boats have ratios 10-15
- Cruiser-Racers have ratios 16-20
- Racers have ratios above 20
- High-Performance Racers have ratios above 24
Sail-area/displacement ratio (SA/D ratio): 21.91

When buying anti-fouling bottom paint, it's nice to know how much to buy. The surface of the wet bottom is about 10m² (107 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.

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 HD 20 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.