Review of Medusa (Griffiths)

The hull is made of wood.
Some boats has a hull made of Fibreglass.

The Medusa (Griffiths) 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.

The Medusa (Griffiths) has been built with different keel alternatives.

Full keel

One option is a long keel. A full keel provide a better directional stability than a similar boat with a fin keel; on the other hand, better directional stability means also that the boat is more difficult to handle in a harbour with less space.

The boat can enter even shallow marinas as the draft is just about 0.76 - 0.86 meter (2.49 - 2.79 ft) dependent on the load. See immersion rate below.

Bilge keel

Another option is a bilge keel. A bilge keel is a double keel, which allows the boat to be beached. Bilge keels are the most popular keel for tidal waters.

The boat can enter even shallow marinas as the draft is just about 0.76 - 0.86 meter (2.49 - 2.79 ft) dependent on the load. See immersion rate below.

Medusa (Griffiths) may be equipped with an inboard Volvo Penta diesel engine at 7 hp (5 kW). Calculated max speed is about 3.9 knots

What is Capsize Screening Formula (CSF)?

The capsize screening value for Medusa (Griffiths) 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 5.8 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 Medusa (Griffiths) is about 93 kg/cm, alternatively 523 lbs/inch.
Meaning: if you load 93 kg cargo on the boat then it will sink 1 cm. Alternatively, if you load 523 lbs cargo on the boat it will sink 1 inch.

What is Motion Comfort Ratio (MCR)?

The Motion Comfort Ratio for Medusa (Griffiths) is 22.1.

What is L/B (Length Beam Ratio)?

The l/b ratio for Medusa (Griffiths) is 3.06.

What is Displacement Length Ratio?

The DL-ratio for Medusa (Griffiths) is 317 which categorizes this boat among 'medium weight cruisers'.

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): 14.59

When buying anti-fouling bottom paint, it's nice to know how much to buy. The surface of the wet bottom is about 14m² (150 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 Medusa (Griffiths) 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.