Review of B 25 Mk II

Both the hull and the deck 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 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 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 4-5 berths, a galley, 100.0 liter fresh water capacity and toilet facility.

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

The B 25 Mk II is equipped with 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 B 25 Mk II is equipped with a fin keel. A boat with a fin keel is more manoeuvrable but has less directional stability than a similar boat with a full 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.

B 25 Mk II 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.

The boat may be equipped with an inboard Yanmar 1GM diesel engine at 7 hp (5 kW). The speed is 6.0 knots.

The fuel tank, which is made of stainless steel, has a capacity of 20.0 liters (5 US gallons, 4 imperial gallons).

What is Capsize Screening Formula (CSF)?

The capsize screening value for B 25 Mk II is 2.13, 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 B 25 Mk II is about 103 kg/cm, alternatively 579 lbs/inch.
Meaning: if you load 103 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 579 lbs cargo on the boat it will sink 1 inch.

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for B 25 Mk II is 17.5.

What is L/B (Length Beam Ratio)?

The l/b ratio for B 25 Mk II is 2.86.

What is a Ballast Ratio?

The ballast ratio for B 25 Mk II is 50%.

What is Displacement Length Ratio?

The DL-ratio for B 25 Mk II is 257 which categorizes this boat among 'light crusers & offshore racers'.

When buying anti-fouling bottom paint, it's nice to know how much to buy. The surface of the wet bottom is about 18m² (193 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.

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