Review of Idylle 13.50

The Idylle 13.50 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 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. As the surface of a fin type keel is just a fraction of the total wet surface, the difference between an iron keel and a lead keel can in reality be ignored for cruising yachts.

The boat can enter most marinas as the draft is just about 1.76 - 1.86 meter (5.77 - 6.07 ft) dependent on the load. See immersion rate below.

Idylle 13.50 is typically equipped with an inboard Perkins 4.108 diesel engine at 50.0 hp (37 kW), which gives a max speed about 6.6 knots.

The transmission is a shaft drive. A shaft drive will in the long run require less maintenence than other types of drive e.g. a sail drive.

What is Capsize Screening Formula (CSF)?

The capsize screening value for Idylle 13.50 is 1.92, indicating that this boat could - if evaluated by this formula alone - 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 7.9 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 Idylle 13.50 is about 288 kg/cm, alternatively 1615 lbs/inch.
Meaning: if you load 288 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 1615 lbs cargo on the boat it will sink 1 inch.

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for Idylle 13.50 is 28.8.

What is L/B (Length Beam Ratio)?

The l/b ratio for Idylle 13.50 is 3.15.

What is a Ballast Ratio?

The ballast ratio for Idylle 13.50 is 38%.

What is Displacement Length Ratio?

The DL-ratio for Idylle 13.50 is 240 which categorizes this boat among 'light crusers & offshore racers'.

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): 21.47

When buying anti-fouling bottom paint, it's nice to know how much to buy. The surface of the wet bottom is about 46m² (495 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.

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If you have any comments to the review, improvement suggestions, or the like, feel free to contact us. Criticism helps us to improve.