Oyster 55

Sailboat specifications

The Oyster 55 is a 56’4” (17.15m) cruising sailboat designed by Holman & Pye (United Kingdom). She was built since 1986 (and now discontinued) by Oyster (United Kingdom) with 49 hulls completed.

Oyster 55's main features

Model: Oyster 55
Hull type: Monohull
Category: Offshore cruising sailboat
Sailboat builder: Oyster
Sailboat designer: Holman & Pye
Country: United Kingdom
Construction: Hull and deck: GRP (glass reinforced polyester)
Number of hulls built: 49
First built hull: 1986
Last built hull: Discontinued
Appendages: Keel : fin without bulb
Helm: Single helm wheel
Rudder: Single rudder on skeg
Unsinkable: No
Trailerable: No
Standard public price ex. VAT (indicative only): N/A €

Oyster 55's main dimensions

Hull length: 56’ 4”17.15 m
Waterline length: 45’ 5”13.85 m
Beam (width): 15’ 8”4.8 m
Draft: 7’ 6”2.3 m
Light displacement (M_LC): 50993 lb23130 kg
Ballast weight: 13228 lb6000 kg

Oyster 55's rig and sails

Upwind sail area: 1595 ft²148.2 m²
Rigging type: Cutter Marconi (in-mast furling mainsail) masthead
Rotating spars: No
Number of levels of spreaders: 2
Spreaders angle: 0 °
Spars construction: Aluminum spars
Standing rigging: 1x19 strand wire

Oyster 55'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.: 197 ft²/T18.26 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.: 247
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.: 26 %
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.: 9.03 knots