Sirius 40 DS — Information, Review, Specs

Marc-Oliver von Ahlen·2015·Sirius -Werft GmbH
Approximate drawing

Hover a measurement to read its value

Hull type
Monohull · fin
Rig
Fractional Sloop
LOA
42.32' · 12.9 m
Displ.
25,574 lbs · 11,600 kg
First year
2015

The Sirius 40 DS represents the zenith of the "onelevel living" philosophy championed by the Plönbased SiriusWerft shipyard. As the flagship of the range, this 40foot deck saloon cruiser is engineered to provide the internal volume typically associated with a 45 to 50foot yacht, achieved through a sophisticated trilevel interior arrangement. Launched following an extensive fiveyear development cycle, the 40 DS is built to Category A (Ocean) standards, emphasizing a "goanywhere" capability without sacrificing the panoramic visibility that defines the brand. Unlike massproduction yachts, the 40 DS is a semicustom vessel, with each hull tailored to the owner's specific cruising requirements, ranging from technical workshop installations to multicabin configurations. Detailed technical insights and design philosophy can be found directly through the manufacturer at Sirius Yachts.

Measurements

Dimensions 01

LOA
42.32 ft
LWL
36.65 ft
Beam
13.39 ft
Draft
7.55 ft
Max headroom
-
Air draft
-

Construction & hull 02

Construction
Fiberglass
Hull type
Monohull
Keel type
Fin
Rudder
1× —
Ballast
7606 lbs (Lead/Iron)
Displacement
25574 lbs
Water
106 gal
Fuel
53 gal

Rig & sails 03

Rig type
Fractional Sloop
P · main luff
-
E · main foot
-
I · fore ht.
-
J · fore base
-
Forestay (est)
-
Sail area
875.11 sqft

Calculations 04

SA/D ratio
16.13
Ballast/Disp.
29.74
D/L ratio
231.91
Comfort ratio
32.55
Capsize screening
1.82
Hull speed
8.11 kn

Sailing Performance & Handling

The Sirius 40 DS is a heavy-displacement cruiser that prioritizes stability and ease of handling over raw regatta speed. Despite its high topsides and significant 11.6-ton light displacement, the yacht is noted for its surprising agility. According to editorial testing by Yachting World, the boat exhibits a stiff, upright posture even in gusty conditions, thanks to a high ballast ratio and a modern hull shape designed by Marc-Oliver von Ahlen.

The yacht is typically rigged with a self-tacking jib as standard, making it exceptionally easy to handle short-handed. For lighter airs, most owners opt for a larger overlapping genoa or a "Gennaker" on a furler. One of the most distinctive aspects of its performance profile is the choice of appendages: buyers can select from a deep fin keel, a lifting keel for shallow-water exploration, or a twin-keel (bilge keel) setup that allows the boat to dry out upright. The twin-rudder configuration ensures that even when heeled, the boat maintains a firm grip on the water, reducing the risk of broaching during heavy-weather reaches.

Interior Comfort & Variations

The interior of the Sirius 40 DS is widely regarded as a masterclass in nautical joinery and space optimization. The "Deck Saloon" design places the seating area and a 360-degree view galley on the same level as the cockpit, facilitating a seamless transition between indoor and outdoor living. Below the saloon, the yard utilizes the midships volume to house a secondary double cabin or a technical room, a feat of packaging that Practical Boat Owner described as making the boat feel like a "Tardis."

Variations are a hallmark of the 40 DS. While the standard layout features a massive owner's suite in the bow and a midships cabin, the shipyard has engineered over a dozen internal configurations. These range from a two-cabin "luxury couple" layout with a dedicated walk-in workshop and office to a four-cabin variant that can accommodate larger families. The use of solid mahogany or optional oak finishes, combined with nearly two meters of headroom throughout the vessel, creates an atmosphere of robust luxury. The shipyard’s commitment to semi-customization means that "siblings" of the 40 DS are rarely identical, with variations often including specific galley heights or custom navigation stations designed to the owner's physical stature.

The Sirius 40 DS has garnered significant attention in the sailing media for its uncompromising approach to the "ultimate blue-water cruiser" concept. It was prominently featured in a comprehensive video review by Yachting Monthly, where it was lauded for its innovative use of space and build quality. The boat’s reputation is often bolstered by its appearances at major European boat shows like Boot Düsseldorf, where it is frequently cited as a benchmark for custom yacht construction in the mid-size category.

Known Issues & Buyer’s Checklist

Because the Sirius 40 DS is a low-volume, high-end build, it does not suffer from the common structural failures seen in high-production light-displacement yachts. However, the complexity of its systems necessitates a rigorous inspection:

  • System Density: The tri-level floor plan results in highly concentrated plumbing and electrical runs. A surveyor should check the accessibility and condition of seacocks and pumps located in the deeper "basement" sections of the hull.
  • Window Seals: The large panoramic deck saloon windows are central to the boat’s appeal. Prospective buyers should inspect the specialized bonding for any signs of UV degradation or weeping, as these are custom-manufactured units.
  • Weight Sensitivity: While the 40 DS handles its displacement well, owners often add heavy equipment (washers, generators, dive compressors) into the vast storage voids. It is vital to verify that the boat’s trim has not been negatively affected by aftermarket additions.
  • Lifting Keel Mechanism: On variants equipped with a swing or lifting keel, the hydraulic rams and pivot pins require specific maintenance intervals. Any "clunking" while under sail or at anchor may indicate wear in the grounding plates or bushings.

Community & Resources

The primary hub for owners is the Sirius Owners Group, which, while largely German-speaking, has a growing international contingent. The manufacturer, Sirius-Werft, maintains an unusually close relationship with its owners, often hosting "owner days" and providing direct technical support from the factory in Plön. This direct line to the builder often bypasses the need for third-party technical wikis, as the shipyard keeps meticulous records of every semi-custom build.

The Verdict

The Sirius 40 DS is an outlier in the modern market: a heavy, expensive, and meticulously hand-built cruiser that rejects the "charter-friendly" trends of its competitors in favor of genuine long-distance comfort and safety.

Pros:

  • Unrivaled interior volume and 360-degree visibility from the saloon.
  • Exceptional build quality with high-grade materials and solid joinery.
  • Versatile keel options including a highly effective twin-keel arrangement.
  • Category A rating with a focus on short-handed offshore sailing.

Cons:

  • Significantly higher price point compared to mass-produced 40-footers.
  • High displacement limits light-wind sailing performance.
  • Complex internal systems may require professional maintenance in remote areas.

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