Review of Finngulf 391
Basic specs.
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The hull is made of fibreglass. Generally, a hull made of fibreglass requires only a minimum of maintenance during the sailing season.
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.
The Finngulf 391 has been built with different keel alternatives.
Unknown keel type
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 only enter major marinas as the draft is about 1.95 - 2.05 meter (6.40 - 6.70 ft) dependent on the load. See immersion rate below.
Fin keel
The Finngulf 391 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.
Finngulf 391 can only enter major marinas as the draft is about 2.03 - 2.13 meter (6.66 - 6.96 ft) dependent on the load. See immersion rate below.
The boat may be equipped with an inboard Volvo Penta diesel engine
The transmission is a saildrive.
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.
What is Capsize Screening Formula (CSF)?
The capsize screening value for Finngulf 391 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 7.4 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 Finngulf 391 is about 218 kg/cm, alternatively 1221 lbs/inch.
Meaning: if you load 218 kg cargo on the boat then it will sink 1 cm.
Alternatively, if you load 1221 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.
What is Motion Comfort Ratio (MCR)?
The Motion Comfort Ratio for Finngulf 391 is 25.5.
What is L/B (Length Beam Ratio)?
The l/b ratio for Finngulf 391 is 3.38.
The ballast ratio for Finngulf 391 is 42%.
What is Displacement Length Ratio?
The DL-ratio for Finngulf 391 is 232 which categorizes this boat among 'light crusers & offshore racers'.
What is SA/D (Sail Area Displacement ratio)?
The SA/D for Finngulf 391 with ISO 8666 reference sail is 21.0, with a 135% genua the SA/D is 24.4.
What is Relative Speed Performance?
The Relative Speed Performance for Finngulf 391 is 69
Maintenance
When buying anti-fouling bottom paint, it's nice to know how much to buy.
The surface of the wet bottom is about 38m2 (409 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 fractional 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.
| Fractional rig | ||||
| Usage | Length | Diameter | ||
| Mainsail halyard | 40.0 m | (131.4 feet) | 12 mm | (1/2 inch) |
| Jib/genoa halyard | 40.0 m | (131.4 feet) | 12 mm | (1/2 inch) |
| Spinnaker halyard | 40.0 m | (131.4 feet) | 12 mm | (1/2 inch) |
| Jib sheet | 12.0 m | (39.3 feet) | 14 mm | (0.55 inch) |
| Genoa sheet | 12.0 m | (39.3 feet) | 14 mm | (0.55 inch) |
| Mainsheet | 29.9 m | (98.2 feet) | 14 mm | (0.55 inch) |
| Spinnaker sheet | 26.3 m | (86.4 feet) | 14 mm | (0.55 inch) |
| Cunningham | 5.0 m | (16.4 feet) | 12 mm | (1/2 inch) |
| Kickingstrap | 10.0 m | (32.8 feet) | 12 mm | (1/2 inch) |
| Clew-outhaul | 10.0 m | (32.8 feet) | 12 mm | (1/2 inch) |
| Fractional rig | ||||
| Usage | Length | Diameter | ||
| Mainsail halyard | 40.0 m | (131.4 feet) | 12 mm | (1/2 inch) |
| Jib/genoa halyard | 40.0 m | (131.4 feet) | 12 mm | (1/2 inch) |
| Spinnaker halyard | 40.0 m | (131.4 feet) | 12 mm | (1/2 inch) |
| Jib sheet | 12.0 m | (39.3 feet) | 14 mm | (0.55 inch) |
| Genoa sheet | 12.0 m | (39.3 feet) | 14 mm | (0.55 inch) |
| Mainsheet | 29.9 m | (98.2 feet) | 14 mm | (0.55 inch) |
| Spinnaker sheet | 26.3 m | (86.4 feet) | 14 mm | (0.55 inch) |
| Cunningham | 5.0 m | (16.4 feet) | 12 mm | (1/2 inch) |
| Kickingstrap | 10.0 m | (32.8 feet) | 12 mm | (1/2 inch) |
| Clew-outhaul | 10.0 m | (32.8 feet) | 12 mm | (1/2 inch) |
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