Marlow Hunter 31 Shoal draft

Sailboat specifications

The Marlow Hunter 31 is a 31’11” (9.73m) cruising sailboat designed by Glenn Henderson (United States). She is built since 2015 by Marlow Hunter (United States). The Shoal draft version is offered with a short keel fitted with large winglets. This configuration provides an interesting draft / low center of gravity / upwind performance trade-off.

The Marlow Hunter 31 is as well listed, on Boat-Specs.com, in Deep draft and Furling mainsail version (see all the versions compared).

Marlow Hunter 31's main features

Model: Marlow Hunter 31
Version: Shoal draft
Hull type: Monohull
Category: Cruising sailboat
Sailboat builder: Marlow Hunter
Sailboat designer: Glenn Henderson
Country: United States
Construction: GRP (glass reinforced polyester):
- Hull: Single skin fiberglass vinylester with Kevlar reinforcements
- Deck: Sandwich balsa fiberglass vinylester
First built hull: 2015
Last built hull: Still in production
Appendages: Keel : wing keel
Helm: Single helm wheel
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 €

Marlow Hunter 31's main dimensions

Overall length: 32’ 4”9.86 m
Hull length: 31’ 11”9.73 m
Waterline length: 29’ 8”9.04 m
Beam (width): 11’ 10”3.61 m
Draft: 4’ 5”1.35 m
Mast height from D_WL: 46’ 7”14.19 m
Light displacement (M_LC): 12000 lb5443 kg
Ballast weight: 3525 lb1599 kg
Ballast type: Cast iron

Marlow Hunter 31's rig and sails

Upwind sail area: 581 ft²54 m²
I iFore triangle height (from mast foot to fore stay top attachment): 35’ 10”10.9 m
J iFore triangle base (from mast foot to bottom of forestay): 11’ 4”3.43 m
P iMainsail hoist measurement (from tack to head): 36’ 6”11.11 m
E iMainsail foot measurement (from tack to clew): 13’ 10”4.22 m
Rigging type: Sloop Marconi (in-mast furling mainsail) fractional
Mast configuration: Deck stepped mast
Rotating spars: No
Number of levels of spreaders: 2
Spreaders angle: Swept-back (Bergström)
Spars construction: Aluminum spars
Standing rigging: 1x19 strand wire

Marlow Hunter 31'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.: 188 ft²/T17.45 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.: 209
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.: 29 %
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.: 7.30 knots