Southerly 470

Sailboat specifications

The Southerly 470 is a 47’4” (14.43m) cruising sailboat designed by Stephen Jones Yacht Design (United Kingdom). She was built between 2017 and 2019 by Discovery Yachts Group (United Kingdom).

The Southerly 470 has also been marketed as Southerly 47.

Southerly 470's main features

Model: Southerly 470
Hull type: Monohull
Category: Offshore deck saloon cruising sailboat
Sailboat builder: Discovery Yachts Group
Sailboat designer: Stephen Jones Yacht Design
Sailboat range: Southerly
Country: United Kingdom
Construction: GRP (glass reinforced polyester):
Single skin bottom, sandwich sides and deck: fiberglass vinylester vacuum bagged
First built hull: 2017
Last built hull: 2019
Appendages: Lifting keel : swing keel
Helm: Twin helm wheels
Rudder: Twin spade rudders
Unsinkable: No
Trailerable: No
EC design category iThe CE design category indicates the ability to cope with certain weather conditions (the sailboat is designed for these conditions) A: Wind < force 9, Waves < 10m B: Wind < force 8, Waves < 8m C: Wind < force 6, Waves < 4m D: Wind < force 4, Waves < 0,5m: A
Standard public price ex. VAT (indicative only): About
565 000 €
(2017)

Southerly 470's main dimensions

Hull length: 47’ 4”14.43 m
Waterline length: 42’ 10”13.05 m
Beam (width): 14’ 7”4.46 m
Draft: 10’ 2”3.12 m
Draft when appendages up: 3’ 4”1 m
Mast height from D_WL: 71’ 10”21.87 m
Light displacement (M_LC): 38043 lb17256 kg
Ballast weight: 13492 lb6120 kg

Southerly 470's rig and sails

Upwind sail area: 1406 ft²130.6 m²
Mainsail area: 625 ft²58.1 m²
Genoa area: 780 ft²72.5 m²
Jib area: 491 ft²45.6 m²
Rigging type: Sloop Marconi fractional
Mast configuration: Deck stepped mast
Rotating spars: No
Number of levels of spreaders: 2
Spreaders angle: Swept-back
Spars construction: Aluminum spars (carbon fiber spars as an option)
Standing rigging: 1x19 strand wire

Southerly 470'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.: 211 ft²/T19.56 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.: 220
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.: 35 %
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.: 8.77 knots