RM 1050 Twin keel

Sailboat specifications

The RM 1050 is a 34’5” (10.47m) fast cruising sailboat designed by Marc Lombard Yacht Design Group (France). She was built between 1998 and 2011 by Fora Marine (France). The Twin keel version allows a shallower draft while maintaining performance thanks to the asymmetric fins with bulb. As a bonus beaching becomes easy and stable.

RM 1050's main features

Model: RM 1050
Version: Twin keel
Hull type: Monohull
Category: Offshore fast cruising sailboat
Sailboat builder: Fora Marine
Sailboat designer: Marc Lombard Yacht Design Group
Sailboat range: RM
Country: France
Construction: Hull and deck: plywood with glass/epoxy stratification
First built hull: 1998
Last built hull: 2011
Appendages: Twin keel : twin asymmetric fin 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 €

RM 1050's main dimensions

Overall length: 34’ 10”10.6 m
Hull length: 34’ 5”10.47 m
Waterline length: 32’ 2”9.8 m
Beam (width): 13’3.95 m
Waterline beam (width): 9’ 10”3 m
Draft: 5’ 2”1.6 m
Mast height from D_WL: 51’ 6”15.7 m
Light displacement (M_LC): 9039 lb4100 kg
Maximum displacement (M_LDC): 12125 lb5500 kg
Ballast weight: 4550 lb2064 kg
Ballast type: Cast iron
French customs tonnage: 13.58 Tx

RM 1050's rig and sails

Upwind sail area: 775 ft²72 m²
Downwind sail area: 1324 ft²123 m²
Mainsail area: 409 ft²38 m²
Genoa area: 366 ft²34 m²
Jib area: 172 ft²16 m²
Symmetric spinnaker area: 915 ft²85 m²
I iFore triangle height (from mast foot to fore stay top attachment): 47’ 2”14.4 m
J iFore triangle base (from mast foot to bottom of forestay): 12’ 8”3.88 m
P iMainsail hoist measurement (from tack to head): 41’ 7”12.69 m
E iMainsail foot measurement (from tack to clew): 16’ 1”4.91 m
Rigging type: Cutter Marconi masthead
Mast configuration: Deck stepped mast
Rotating spars: No
Number of levels of spreaders: 2
Spreaders angle: 25 °
Spars construction: Aluminum spars
Standing rigging: 1x19 strand wire

RM 1050's performances

HN (French rating) iHN or "Handicap Nationale" is an empirical rating system used in France allowing various monohulls, of different sizes and designs, to race each other fairly. It is particularly suitable for cruiser and cruiser-racer. Therefore, by comparing these values, we can have an indication of the relative speed of 2 boats.: 24.0
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.: 303 ft²/T28.11 m²/T
Downwind 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.: 517 ft²/T48.02 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.: 123
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.: 50 %
Prismatic coefficient iThe prismatic coefficient is obtained by dividing the volume of the boat (mass divided by the density of water) by the waterline length multiplied by the area of the maximum transverse section. This coefficient describes the effectiveness of a sailboat for a certain speed range: lower is the coefficient (<0.45), more effective the yacht is below its hull speed; higher the coefficient is, more the boat is suitable for planning speed.: 0.50
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.: 32549 lb.ft4500 kg.m @ 50.00 °
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.: 7.60 knots