Merlin 28 Twin keel

Sailboat specifications

The Merlin 28 is a 27’1” (8.25m) cruising sailboat designed by Dubois Naval Architects (United Kingdom). She was built between 1984 and 1990 by Westerly (United Kingdom) with 151 hulls completed. The Twin keel version allows a shoal draft and stability while beaching.

The Merlin 28 is as well listed, on Boat-Specs.com, in Fin keel version (see all the versions compared).

Merlin 28's main features

Model: Merlin 28
Version: Twin keel
Hull type: Monohull
Category: Cruising sailboat
Sailboat builder: Westerly
Sailboat designer: Dubois Naval Architects
Country: United Kingdom
Construction: Hull and deck: GRP (glass reinforced polyester)
Number of hulls built: 151
First built hull: 1984
Last built hull: 1990
Appendages: Twin keel : fin without bulb
Helm: Single tiller
Rudder: Single transom hung rudder
Unsinkable: No
Trailerable: No
Standard public price ex. VAT (indicative only): N/A €

Merlin 28's main dimensions

Overall length: 28’ 8”8.75 m
Hull length: 27’ 1”8.25 m
Waterline length: 23’ 7”7.2 m
Beam (width): 9’ 11”3.03 m
Draft: 3’ 5”1.03 m
Mast height from D_WL: 36’ 8”11.19 m
Light displacement (M_LC): 8036 lb3645 kg
Ballast weight: 3329 lb1510 kg

Merlin 28's rig and sails

Upwind sail area: 443 ft²41.2 m²
Downwind sail area: 618 ft²57.4 m²
Mainsail area: 208 ft²19.3 m²
Genoa area: 236 ft²21.9 m²
Jib area: 129 ft²12 m²
Stormjib area: 46 ft²4.3 m²
Symmetric spinnaker area: 410 ft²38.1 m²
Rigging type: Sloop Marconi 7/8
Mast configuration: Deck stepped mast
Rotating spars: No
Number of levels of spreaders: 1
Spreaders angle: Swept-back
Spars construction: Aluminum spars
Standing rigging: 1x19 strand wire continuous

Merlin 28'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.: 187 ft²/T17.4 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.: 261 ft²/T24.24 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.: 277
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.: 41 %
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.: 6.51 knots