Udkik.dk

Review of Lohi 25


Lohi 25
Lohi 25 anno 1980.

Basic specs.

sail specifications
The Lohi 25 is a small sailboat designed by the Finnish maritime architect Guy-Christer Lönngren.

Looking for a new boat? Find a Lohi 25 or similar boat for sale

Hull
Deck plan
Deck plan of Lohi 25.

Interior
Interior
Interior of Lohi 25 anno 1980.
Front cabin
Front cabin of Lohi 25 anno 1980.

Cockpit
Cockpit
Cockpit of Lohi 25 anno 1980.
Rig
Rig
Rig of Lohi 25 anno 1980.
The boat 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.

Keel
Keel
Keel of Lohi 25 anno 1980. Rudder and sail drive

The keel is made of lead. Compared with iron, lead has the advantage of being 44% heavier, which allows a smaller keel and hence less water resistance and higher speed.

The boat can enter most marinas as the draft is just about 1.50 - 1.60 meter (4.92 - 5.22 ft) dependent on the load. See immersion rate below.


Sailing characteristics

This section covers widely used rules of thumb to describe the sailing characteristics. Please note that even though the calculations are correct, the interpretation of the results might not be valid for extreme boats.

Stability and Safety

What is Capsize Screening Formula (CSF)?

The capsize screening value for Lohi 25 is 2.16, indicating that this boat would not be accepted to participate in ocean races.


Theoretical Maximum Hull Speed

What is Theoretical Maximum Hull Speed?

The theoretical maximal speed of a displacement boat of this length is 6.3 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.


Immersion rate

The immersion rate is defined as the weight required to sink the boat a certain level. The immersion rate for Lohi 25 is about 127 kg/cm, alternatively 714 lbs/inch.
Meaning: if you load 127 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 714 lbs cargo on the boat it will sink 1 inch.


Sailing statistics

This section is statistical comparison with similar boats of the same category. The basis of the following statistical computations is our unique database with more than 26,000 different boat types and 350,000 data points.

Motion Comfort Ratio

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for Lohi 25 is 16.9.

Low High 42% 0 50 100
Comparing this ratio with similar sailboats show that it is more comfortable than 42% of all similar sailboat designs. This comfort value is just below average.


L/B (Length Beam Ratio)

What is L/B (Length Beam Ratio)?

The l/b ratio for Lohi 25 is 2.75.

Slim Wide 79% 0 50 100
Compared with other similar sailboats it is more spacy than 79% of all other designs. It seems that the designer has chosen a significantly more spacy hull design.


Ballast Ratio

What is a Ballast Ratio?

The ballast ratio for Lohi 25 is 38%.

Low High 42% 0 50 100
This ballast ratio shows a righting moment that is higher than 42% of all similar sailboat designs. A righting moment (ability to resist heeling) just below average.


D/L (Displacement Length Ratio)

What is Displacement Length Ratio?

The DL-ratio for Lohi 25 is 196 which categorizes this boat among 'light racers'.

Heavy Light 66% 0 50 100
66% 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)

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

The SA/D for Lohi 25 with ISO 8666 reference sail is 14.3, with a 135% genua the SA/D is 17.3.

Low High 27% 0 50 100
The SA/D ratio indicates that it is faster than 27% of all similar sailboat designs in light wind.


Over- / underrigged

Low High 46% 0 50 100
The Lohi 25 has more rig than 46% of all similar sailboats, which indicates that the boat is slightly underrigged.


RSP (Relative Speed Performance)

What is Relative Speed Performance?

The Relative Speed Performance for Lohi 25 is 58

Slow Fast 58% 0 50 100
The relative speed performance is 58 which means that a it is faster than 58% of all similar sailboat designs.


Maintenance

Bottom Paint

When buying anti-fouling bottom paint, it's nice to know how much to buy. The surface of the wet bottom is about 22m2 (236 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.


Rig

Dimensions of sail for masthead rig.

mainsail specifications genoa specifications spinnaker specifications

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.



Guiding dimensions of running rig
UsageLengthDiameter
Mainsail halyard 22.2 m(72.8 feet)8 mm(5/16 inch)
Jib/genoa halyard22.2 m(72.8 feet)8 mm(5/16 inch)
Spinnaker halyard22.2 m(72.8 feet)8 mm(5/16 inch)
Jib sheet 7.7 m(25.3 feet)10 mm(3/8 inch)
Genoa sheet7.7 m(25.3 feet)10 mm(3/8 inch)
Mainsheet 19.2 m(63.2 feet)10 mm(3/8 inch)
Spinnaker sheet16.9 m(55.6 feet)10 mm(3/8 inch)
Cunningham2.3 m(7.6 feet)8 mm(5/16 inch)
Kickingstrap4.6 m(15.2 feet)8 mm(5/16 inch)
Clew-outhaul4.6 m(15.2 feet)8 mm(5/16 inch)

Boat owner's ideas

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.



Finally

We are always looking for new photos. If you can contribute with photos for Lohi 25 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.



References