Swan 371's main features
Model
Swan 371
Hull type
Monohull
Category
Cruiser-racer sailboat
Sailboat builder
Sailboat designer
Country
Finland
Construction
Hull and deck: GRP (glass reinforced polyester)
Number of hulls built
87
First built hull
1979
Last built hull
1987
Appendages
Keel : fin without bulb
Helm
Single helm wheel
Rudder
Single spade rudder
Unsinkable
No
Trailerable
No
Standard public price ex. VAT (indicative only)
Swan 371's main dimensions
Hull length
36’ 10”11.23 m
Waterline length
29’ 8”9.06 m
Beam (width)
11’ 4”3.45 m
Draft
6’ 11”2.1 m
Light displacement (MLC)
15432 lb7000 kg
Ballast weight
5732 lb2600 kg
Ballast type
Lead
Swan 371's rig and sails
Upwind sail area
603 ft²56 m²
I
iFore triangle height (from mast foot to fore stay top attachment)46’ 10”14.25 m
J
iFore triangle base (from mast foot to bottom of forestay)15’ 1”4.6 m
P
iMainsail hoist measurement (from tack to head)41’12.5 m
E
iMainsail foot measurement (from tack to clew)12’3.65 m
Rigging type
Sloop Marconi masthead
Mast configuration
Keel stepped mast
Rotating spars
No
Number of levels of spreaders
2
Spreaders angle
0 °
Spars construction
Aluminum spars
Standing rigging
1x19 strand wire
Swan 371's performances
Upwind sail area to displacement
iThe ratio sail area to displacement is obtained by dividing the sail area by the boat's displaced volume to the power two-thirds.
The ratio sail area to displacement can be used to compare the relative sail plan of different sailboats no matter what their size.
Upwind: under 18 the ratio indicates a cruise oriented sailboat with limited performances especially in light wind, while over 25 it indicates a fast sailboat.165 ft²/T15.3 m²/T
Displacement-length ratio (DLR)
iThe Displacement Length Ratio (DLR) is a figure that points out the boat's weight compared to its waterline length. The DLR is obtained by dividing the boat's displacement in tons by the cube of one one-hundredth of the waterline length (in feet).
The DLR can be used to compare the relative mass of different sailboats no matter what their length:
a DLR less than 180 is indicative of a really light sailboat (race boat made for planning), while a DLR greater than 300 is indicative of a heavy cruising sailboat.267
Ballast ratio
iThe Ballast ratio is an indicator of stability; it is obtained by dividing the boat's displacement by the mass of the ballast. Since the stability depends also of the hull shapes and the position of the center of gravity, only the boats with similar ballast arrangements and hull shapes should be compared.
The higher the ballast ratio is, the greater is the stability.37 %
Critical hull speed
iAs a ship moves in the water, it creates standing waves that oppose its movement. This effect increases dramatically the resistance when the boat reaches a speed-length ratio (speed-length ratio is the ratio between the speed in knots and the square root of the waterline length in feet) of about 1.2 (corresponding to a Froude Number of 0.35) . This very sharp rise in resistance, between speed-length ratio of 1.2 to 1.5, is insurmountable for heavy sailboats and so becomes an apparent barrier. This leads to the concept of "hull speed".
The hull speed is obtained by multiplying the square root of the waterline length (in feet) by 1.34.7.31 knots
Swan 371's auxiliary engine
Engine(s)
1 inboard engine
Engine(s) power
20 HP
Fuel type
Diesel
Fuel tank capacity
37 gal140 liters
Swan 371's accommodations and layout
Cockpit
Closed aft cockpit
Cabin(s)
2
Berth(s) (min./max.)
7 / 9
Head(s)
1
Freshwater tank capacity
66 gal250 liters
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