First 405 Shoal draft

Sailboat specifications

The First 405 is a 39’4” (11.99m) cruiser-racer sailboat designed by Jean Berret (France). She was built between 1985 and 1988 by Bénéteau (France). The Shoal draft version features a shorter keel to grant access to shallow areas.

The First 405 is as well listed, on Boat-Specs.com, in Deep draft version (see all the versions compared).

First 405's main features

Model: First 405
Version: Shoal draft
Hull type: Monohull
Category: Cruiser-racer sailboat
Sailboat builder: Bénéteau
Sailboat designer: Jean Berret
Sailboat range: First
Country: France
Construction: GRP (glass reinforced polyester):
- Hull: Single skin fiberglass polyester
- Deck: Sandwich balsa fiberglass polyester
Number of hulls built: About 250
First built hull: 1985
Last built hull: 1988
Appendages: Keel : fin without bulb
Helm: Single helm wheel
Rudder: Single spade rudder
Unsinkable: No
Trailerable: No
Former French navigation category: 1
Standard public price ex. VAT (indicative only): N/A €

First 405's main dimensions

Overall length: 40’ 11”12.46 m
Hull length: 39’ 4”11.99 m
Waterline length: 35’ 10”10.9 m
Beam (width): 13’3.96 m
Waterline beam (width): 10’ 8”3.27 m
Draft: 5’ 7”1.7 m
Mast height from D_WL: 56’ 7”17.25 m
Fore freeboard: 4’1.23 m
Mid-ship freeboard: 3’ 8”1.12 m
Light displacement (M_LC): 18519 lb8400 kg
Ballast weight: 8157 lb3700 kg
Ballast type: Cast iron

First 405's rig and sails

Upwind sail area: 915 ft²85.03 m²
Downwind sail area: 1579 ft²146.7 m²
Mainsail area: 352 ft²32.7 m²
Genoa area: 563 ft²52.33 m²
Symmetric spinnaker area: 1227 ft²114 m²
Rigging type: Sloop Marconi masthead
Mast configuration: Keel stepped mast
Rotating spars: No
Number of levels of spreaders: 2
Spreaders angle: Swept-back
Spars construction: Aluminum spars
Standing rigging: 1x19 strand wire

First 405'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.: 222 ft²/T20.58 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.: 382 ft²/T35.5 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.: 184
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 %
Wetted area: 339 ft²31.45 m²
Righting moment @ 1° 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.: 974 lb.ft135 kg.m
Maximum transverse section: 21 ft²1.94 m²
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.: 8.01 knots