Review of Bianca 320

The hull is made of hand laid fibreglass while the deck is made of fibreglass. Generally, a hull made of hand laid 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.

Both the hull and the deck is a sandwich construction which improves the indoor climate. Especially when the water is colder than the air in the cabin, then the double hull insulates against cold water and reduce the condense water in the cabin. The core material in the sandwich construction is balsa.

The interior is like many other boats made of mahogany. Mahogany belongs to the hardwood species, known for being water-repellent and resistant to decay. It has an attractive wood grain and holds wood polish and varnish well.
The boat is equipped with 2 cabins, 6 berths, a galley, 120.0 liter fresh water capacity and toilet facility.

Rig of Bianca 320 anno 2003.

The boat has more than one rig.

One option is 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.

Another option is a masthead rig. The advantage of a masthead rig is its simplicity and the fact that a given sail area - compared with a fractional rig - can be carried lower and thus with less heeling moment.

Fin keel

The Bianca 320 is built 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.

Bianca 320 can enter most marinas as the draft is just about 1.75 - 1.85 meter (5.74 - 6.04 ft) dependent on the load. See immersion rate below.

The boat may be equipped with an inboard Yanmar 2GM20FC diesel engine at 18 hp (13 kW). Cruise speed is 5.0 knots. Max speed is 6.0 knots.

The transmission is a saildrive.

The fuel tank, which is made of stainless steel, has a capacity of 60.0 liters (15 US gallons, 13 imperial gallons).

What is Capsize Screening Formula (CSF)?

The capsize screening value for Bianca 320 is 1.91, 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 6.8 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 Bianca 320 is about 167 kg/cm, alternatively 936 lbs/inch.
Meaning: if you load 167 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 936 lbs cargo on the boat it will sink 1 inch.

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for Bianca 320 is 23.0 - 25.7.

What is L/B (Length Beam Ratio)?

The l/b ratio for Bianca 320 is 3.06.

What is a Ballast Ratio?

The ballast ratio for Bianca 320 is 44%.

What is Displacement Length Ratio?

The DL-ratio for Bianca 320 is 267 which categorizes this boat among 'light crusers & offshore racers'.

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

The SA/D for Bianca 320 with ISO 8666 reference sail is 15.9, with a 135% genua the SA/D is 18.8.

As balsa wood is used as sandwich core material special care must be taken in relation to work that require penetration of the sandwich construction in order to to prevent water to get in contact with the balsa wood. Otherwise the balsa wood will eventually rotten and be expensive/impossible to repair.

When buying anti-fouling bottom paint, it's nice to know how much to buy. The surface of the wet bottom is about 29m² (312 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 masthead 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 Bianca 320 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.