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Sirius Yachts

Sirius 40 DS

In production
Sirius 40 DS — photo 1

1 / 6

LI_7351_1-scaled — Sirius-Werft

Summary

42.3 ftLOA65 ftAIR DRAFT8.2 ftDRAFT13.4 ftBEAM
Sailing MonohullSail
Length overall
42.3 ft
Beam
13.4 ft
Draft
3.1–8.2 ft
Air draft
65 ft
Displacement
24,251 lb
Cabins
3
Berths
4–6

* A standard reference image, not the actual boat — shown to help visualise this model's published dimensions.

Best Suited For

Tags are derived from certified class, length, sail area, accommodation and tankage using the criteria described on the Sources page; an editor may add or remove one.

Sailing Ratios

Classic yacht-design ratios worked out from the builder's published figures, each shown against the bands designers read it by.

Sail area / displacement

How much sail the boat carries for its weight — its power in light air.

ModestCruiserPerformanceRacing162024
  • not published: sail area
How it is worked out

sail area (ft²) ÷ (displacement as ft³ of seawater)^⅔

Displacement / length

How heavy the boat is for its waterline length. Lower is lighter and quicker; higher is steadier and roomier.

UltralightLightModerateHeavyVery heavy100180270350Sirius 40 DS: 220
  • 220· Moderate
How it is worked out

displacement (long tons) ÷ (0.01 × waterline length in ft)³

Ballast ratio

The share of the weight carried in the keel — a rough guide to stiffness, though how deep that weight sits matters as much.

LowModerateHigh3040
  • not published: ballast
How it is worked out

ballast ÷ displacement × 100

Comfort ratio

Ted Brewer's measure of how gently a boat moves in a seaway. Higher means a slower, easier motion.

LightCoastalModerate offshoreHeavy offshoreVery heavy20304050Sirius 40 DS: 30.6
  • 30.6· Moderate offshore
How it is worked out

displacement (lb) ÷ (0.65 × (0.7 × LWL + 0.3 × LOA) × beam^1.333), lengths in ft

Capsize screening

A guide from the inquiry after the 1979 Fastnet race: below 2 was taken as suited to ocean passages. It ignores hull shape and where the ballast sits.

Below 22 and above2Sirius 40 DS: 1.85
  • 1.85· Below 2
How it is worked out

beam (ft) ÷ (displacement as ft³ of seawater)^⅓

Hull speed

Roughly the speed a displacement hull reaches before it has to climb its own bow wave.

  • 8.1 kn
How it is worked out

1.34 × √(waterline length in ft), in knots

Most builders publish a light displacement. The ratios were defined on a loaded boat, so every boat here reads a little lighter than a surveyor's figure would — all alike, which keeps them comparable.

Tanks

What the builder publishes about how fast, how strong and how much the boat carries.

Fuel and water on one scale: a tank twice the height holds twice as much.

  • Fuel53 gal
    Water106 gal

    18 gal of water per berth

Dimensions

LOA
42.3 ft (12.9 m)
Hull length
39.3 ft (11.99 m)
LWL
36.6 ft (11.17 m)
Beam
13.4 ft (4.08 m)
Draft (min)
3.1 ft (0.95 m)
Draft (max)
8.2 ft (2.5 m)
Air draft
65 ft (19.8 m)
Displacement
24,251 lb (11,000 kg)
Ballast
—
Cabins
3
Heads
2
Berths
4–6

Sail Plan

Main sail
—
Jib
—
Genoa
—
Sail area
—
Downwind sail area
—
Rig type
—

Engine and Tanks

Engine
51 hp (Volvo Penta)
Engine count
1
Engine manufacturer
Volvo Penta
Propulsion type
saildrive
Fuel capacity
53 gal (200 L)
Fresh water capacity
106 gal (400 L)
Black water capacity
42 gal (160 L)

Construction

Mast material
—
Hull material
hand-laid GRP, vacuum-bonded Corecell M-foam sandwich above the waterline, vinyl ester gelcoat
Deck material
—
Keel type
—
Rudder type
—
Steering wheels
—

Builder's Own Figures

Interior
custom-built for each owner; build time four to six months
Engine
Volvo Penta diesel D2 50, 37.5 kW (51 HP), saildrive
Tanks
standard tanks; larger tanks optional (the page prints 'from … upwards')
Length overall
up to 12.90 m, as printed
Keels
Single fin: 2.30 m (Standard) 2.00 m (Optional) / 1.75 (Optional) Twin keel (optional): 1.45 m Swing keel (optional): 0.95-2.50 m
Beam of hull
4.00 m
Layouts
4-, 5- and 6-berth versions; up to three double cabins
Ballast
3.45 t
Draught basis
range over the keel options printed (swing keel raised to the deepest option)
Displacement basis
as printed, no load stated

Figures read fromsirius-yachts.com/yachts/40ds· Technical dataread 10/18/2026

Layouts & Drawings

4 drawings from the builder's page: general arrangement, sail plan, profile.

About Sirius Yachts

Semi-custom

Family-owned yard in Plön, northern Germany, building hand-made deck-saloon cruising sailboats since 1971 — the Sirius 35 DS and 40 DS, each with a custom interior and a choice of fin, twin or lifting keel.

Sirius Yachts describes itself as boats 'built by craftsmen, with love, since 1971', from the family-owned boat builder that invented the phrase 'deck-saloon'. From its German yard it offers a range of go-anywhere deck-saloon sailboats with hand-crafted, custom-built interiors in mahogany, each available with a single fin keel, a lifting keel or twin keels, and no two yachts from the factory are identical. The yard says it brings nearly half a century of experience building deck-saloon yachts and the experience of more than 650 owners to each new boat: it works through hundreds of design decisions with the buyer — from the rig and sailcloth to the reading lights in the master cabin, and galley drawers made to fit the owner's own cookware — before production begins. The build then takes four to six months; most owners visit the yard several times, receive regular progress pictures by email, and can leave their cutlery, crockery and glassware with the yard so that its storage is made to measure.

Visit brand page

The Sirius Yachts Range

Every model Sirius Yachts publishes, by length — where this one sits in the range.

  1. Sirius 40 DS· this model42.3 ft
  2. Sirius 35 DS34.8 ft

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