Hallberg-Rassy 31 MkII Shoal draft

Sailboat specifications

The Hallberg-Rassy 31 MkII is a 31’7” (9.62m) cruising sailboat designed by Frers Naval Architecture & Engineering (Argentina). She was built between 2005 and 2009 by Hallberg-Rassy (Sweden). The Shoal draft version features a shorter keel to grant access to shallow areas.

The Hallberg-Rassy 31 MkII is as well listed, on Boat-Specs.com, in Standard version (see all the versions compared).

Hallberg-Rassy 31 MkII's main features

Model: Hallberg-Rassy 31 MkII
Version: Shoal draft
Hull type: Monohull
Category: Cruising sailboat
Sailboat builder: Hallberg-Rassy
Sailboat designer: Frers Naval Architecture & Engineering
Country: Sweden
Construction: GRP (glass reinforced polyester):
- Hull: Single skin fiberglass polyester
- Deck: Sandwich balsa fiberglass polyester
Number of hulls built: About 50
First built hull: 2005
Last built hull: 2009
Appendages: Keel : L-shaped keel (with bulb)
Helm: Single tiller
Rudder: Single spade rudder
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): N/A €

Hallberg-Rassy 31 MkII's main dimensions

Hull length: 31’ 7”9.62 m
Waterline length: 27’ 1”8.26 m
Beam (width): 10’ 10”3.3 m
Draft: 4’ 7”1.41 m
Mast height from D_WL: 48’ 11”14.9 m
Light displacement (M_LC): 9921 lb4500 kg
Ballast weight: 4409 lb2000 kg
Ballast type: Lead on deep GRP bilge

Hallberg-Rassy 31 MkII's rig and sails

Upwind sail area: 491 ft²45.6 m²
Mainsail area: 272 ft²25.3 m²
Jib area: 219 ft²20.3 m²
Rigging type: Sloop Marconi 7/8
Mast configuration: Keel stepped mast
Rotating spars: No
Number of levels of spreaders: 2
Spreaders angle: Swept-back
Spars construction: Aluminum spars

Hallberg-Rassy 31 MkII'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.: 180 ft²/T16.73 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.: 226
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.: 44 %
Righting moment @ 30° iThe righting moment is a moment (torque) that tends to restore a boat to its previous position after heeling. Its value corresponds to the torque needed to heel the boat for this angle. Higher the righting moment is for an angle, greater is the stability.: 23869 lb.ft3300 kg.m
Maximum righting moment iThe righting moment is a moment (torque) that tends to restore a boat to its previous position after heeling. Its value corresponds to the torque needed to heel the boat for this angle. Higher the righting moment is for an angle, greater is the stability.: 34718 lb.ft4800 kg.m @ 58.00 °
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.: 6.98 knots