Summary:
Asymmetrical daggerboards provide a performance gain when sailing upwind, both in terms of heading and speed. Symmetrical daggerboards offer a gain in heading only.
For other points of sail, the gain is negligible and depends on wind conditions and the type of daggerboard.
If you're looking for a fast boat, where every knot and degree of upwind lift counts, and you plan to keep the boat light and install the highest-performance sail possible, then a daggerboard configuration should satisfy you with superior performance.
If you're more of a long-distance sailor, with the trade winds at your back, a certain amount of equipment on board, and a need for serenity when sailing in countries far from your home port, then a configuration with keels will be very much in your favor.
All that's left is to know what you want...
For the more curious, let's take a moment to detail this observation.
Explanations:
When embarking on the configuration and/or purchase of a blue water catamaran, one of the key questions to ask is the choice between fixed keels or retractable daggerboards. This article examines why retractable daggerboards, despite their performance superiority, don't necessarily offer other substantial advantages over fixed keels in a long-haul configuration.
Nota bene : This article compares these two configurations only in the context of long-range cruisers, i.e. lightweight boats designed for performance. Furthermore, only retractable daggerboards are discussed, and a distinction must be made between configurations with symmetrical and asymmetrical daggerboards, which do not offer the same performance.
Sailing performance: the advantage of retractable daggerboards
There's no denying that retractable daggerboards are designed to optimize sailing performance, and it works. However, for an identical hull, the performance gain is modest. This observation must also be qualified according to the type of daggerboard installed.
Improved upwind capability: Retractable daggerboards enable catamarans to sail closer to the wind, with a gain of 2 to 5 degrees depending on the type of daggerboard. If the daggerboards are asymmetrical, you can also expect a greater gain in speed.
Speed enhancement :
- Upwind: Higher speeds are observed, but they remain modest with symmetrical drifts. Asymmetrical drifts (2 to 3 knots) can be more interesting.
- On the beam: Daggerboards have an advantage in light winds with a slightly higher speed, but this advantage disappears when winds strengthen and exceed 10 to 15 knots.
- Downwind: Daggerboards benefit with less drag thanks to a smaller wetted surface, although the performance gain is not noticeable.
To sum up, daggerboards do very well upwind, in terms of heading only for symmetrics, and in terms of performance only for asymmetrics. For other points of sail, the performance gain is more moderate, and sometimes even lower in crosswind conditions. It's important to keep in mind that daggerboards provide a performance gain when the boat is kept light, but the more you load your unit, the less interest there is in daggerboards.
Shrink Drift Limitations: Performance at a Cost
While retractable daggerboards bring performance benefits, they also have several disadvantages which we believe can be problematic when considering the configuration of a blue water boat.
- Increased complexity and maintenance: Retractable daggerboard systems are more complex and require regular maintenance to ensure their proper operation. Lifting mechanisms can quickly become hampered if the boat's annual maintenance is not perfect.
- Risk of damage: In the event of collision or grounding, retractable daggerboards are more susceptible to significant damage than fixed keels. Although daggerboards are often sacrificial, shafts remain a particularly critical area that can cause significant water ingress. Repairs can be complex and costly, particularly if the daggerboard shafts are damaged.
For beacher, raising daggerboards dangerously exposes the boat's critical propulsion and rudder systems. Where a keel provides constant protection. - Reduced interior space: Retractable daggerboards require daggerboard wells that take up valuable space inside hulls. This reduces storage and layout options, which can be a constraint for long-term cruising sailors.
- Higher building costs: Building a boat with daggerboards is more complex and requires more work, and these difficulties are automatically reflected in the cost of the boat. This is even truer when asymmetrical daggerboards are installed, which may require separate molds.
In conclusion, if you don't plan to race your boat and prefer peace of mind and ease of use, don't bother with daggerboards. On the other hand, if every knot counts and every degree of upwind lift is crucial, opt for daggerboards, but beware: to see any real difference, you'll need to keep your boat light and optimize its sail area, otherwise you won't be able to outrun your friend who has opted for keels.
Versatility and robustness: the simplicity of fixed pins
While retractable daggerboards are the right choice for those seeking maximum performance, fixed keels offer a series of advantages that make them just as attractive for more general use, or for sailors who prioritize criteria other than pure speed.
- Simplicity and reliability: Fixed keels are solid structures with no moving parts, which considerably reduces the risk of breakdowns and maintenance requirements. This robustness translates into peace of mind for owners, especially during long passages at sea or in harsh environments.
- Grounding Protection: Fixed keels act as protective barriers in the event of grounding, preventing damage to sensitive parts of the boat, such as propellers or rudders. They absorb impacts and can be easily and cost-effectively repaired.
- Easy to land: When servicing or storing on land, or even when beaching, catamarans with fixed keels are easier to wedge and more stable. This simplifies work and reduces landings costs.
- Increased interior space: Without the need to accommodate daggerboard wells inside the hulls, catamarans with fixed keels offer more space for storage and interior fittings. This can mean more comfort and convenience on board, which is particularly appreciated on extended cruises. What's more, fixed keels provide extra buoyancy to take advantage of the boat's increased load capacity.
- Lower manufacturing costs: Fixed keels are generally less expensive to produce than retractable daggerboard systems. For budget-conscious buyers, this initial saving can be a decisive factor.
Evolution of the Quillons : Continuous Improvement
As the boating industry continues to progress, keel design has evolved considerably over the years. Modern keels are designed to offer improved hydrodynamic performance while retaining the traditional advantages of fixed keels.
- Shape optimization: Modern keels are often deeper and more tapered, reducing drag and improving efficiency under sail. This enables keels to offer performance increasingly close to that of daggerboards, especially in strong wind conditions where the additional width can be an asset.
- Innovation in design: advances in aerodynamics have been applied to the naval sector, with optimized keels featuring NACA (National Advisory Committee for Aeronautics) 4 or 6-digit profiles (for rudders). The result is ever more efficient keels, considerably reducing the performance gap between the two configurations.
Conclusion: Performance at what price?
Ultimately, the choice between fixed and retractable keels depends on the priorities and sailing style of each catamaran owner. While retractable daggerboards offer a performance advantage, particularly for race-oriented sailors or those looking to optimize every knot of speed, fixed keels offer simplicity, robustness and interior comfort that should not be underestimated.
For many sailors, especially those who value safety, reliability and ease of maintenance, fixed keels represent the best choice, especially for long-distance voyages that require a certain amount of autonomy and involve loading the boat with a lot of equipment. As always in sailing, every decision involves a compromise, and it's essential to weigh up all the factors carefully to find the boat that best suits your needs and aspirations.
For our part, keels are favored for their robustness and versatility at a lower cost, with performance barely inferior to that of asymmetrical daggerboards and almost equivalent to that of symmetrical daggerboards. Of course, we're only talking about long-distance cruising boats here. Our philosophy at Latitude Mer is to offer you the configuration that suits you best, for a blue water cruising boat.
In our opinion, the keel is the obvious choice for its reliability, the added safety it provides and its ease of maintenance/repair. However, if by any chance a configuration were to be put in place for racing purposes, optimizing the performance of one of our Andaman range boats to the maximum, then a daggerboard design would find its place, combined with a lightweight boat and a high-performance sail.
