Review of Jouët 680

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 Jouët 680 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.

The Jouët 680 has been built with different keel alternatives.

CentreBoard

One option is a centreboard keel. A centreboard keel is a pivoting lifting keel, allowing to sail both coastal and inland waters.

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 sail close to the beach as the draft is just 0.30 - 0.40 meter (0.98 - 1.28 ft) dependent of the load. See immersion rate below.

Fin keel

Another option is 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.

This keel is also made of iron.

The boat can enter even shallow marinas as the draft is just about 1.10 - 1.20 meter (3.61 - 3.91 ft) dependent on the load. See immersion rate below.

Fin keel

Another option is 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.

Jouët 680 can enter even shallow marinas as the draft is just about 1.10 - 1.20 meter (3.61 - 3.91 ft) dependent on the load. See immersion rate below.

What is Theoretical Maximum Hull Speed?

The theoretical maximal speed of a displacement boat of this length is 6.0 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 Jouët 680 is about 100 kg/cm, alternatively 564 lbs/inch.
Meaning: if you load 100 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 564 lbs cargo on the boat it will sink 1 inch.

What is L/B (Length Beam Ratio)?

The l/b ratio for Jouët 680 is 2.63.

Compared with other similar sailboats it is more spacy than 73% of all other designs. It seems that the designer has chosen a slightly more spacy hull design.

What is a Ballast Ratio?

The ballast ratio for Jouët 680 is 53%.

This ballast ratio shows a righting moment that is higher than 93% of all similar sailboat designs. A righting moment (ability to resist heeling) significantly above average.

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.

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 Jouët 680 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.