Insights from Catamaran Conversations, Episode 4 — featuring Phil Berman (Balanced Catamarans), Patrick Shaughnessy (Far Yacht Design), and Herb McCormick
If there’s one design choice that truly separates a performance cruising catamaran from the rest of the fleet, it’s what’s happening beneath the waterline. In this installment of Catamaran Conversations, our panel dives deep into the daggerboard versus fixed keel debate — and the consensus is clear, even if the trade-offs are real.
The Fundamental Job: Resisting Leeway
Unlike a monohull, a catamaran doesn’t need to package ballast below the water. The sole mission of the underbody appendages is to resist leeway and create lift, allowing the boat to track upwind rather than sliding sideways. Designers have traditionally taken two paths to accomplish this: small fixed keels or retractable daggerboards.
The distinction matters more than many buyers realize. Fixed keels on production catamarans tend to be relatively shallow and wide — a geometry that simply can’t generate the same lateral resistance as a well-designed daggerboard. The result, according to Phil Berman, is that a typical production keeled catamaran sails at roughly 55 to 60 degrees to the true wind, while a daggerboard-equipped cat can tighten that angle down into the 45-degree range. That’s a massive difference when you’re trying to claw off a lee shore or work your way around a headland.
Where the Performance Gap Is Greatest
The VPP (Velocity Prediction Program) data and real-world experience align here. Daggerboards deliver their biggest advantage in light to moderate winds — up to about 15 knots of true wind — where the boards are actively generating lift and dramatically reducing leeway. As wind builds beyond that, the performance gap narrows somewhat. Patrick Shaughnessy attributes this partly to the dynamic sea state that accompanies stronger winds, where both boat types become somewhat less stable in a hydrodynamic sense.
Phil shared a vivid example from a Caribbean Multihull Challenge a couple of years back. Sailing aboard a Balance 442, he found himself roughly even with a similar-length keeled cat on a reaching leg. The moment they rounded a mark and began beating to windward with the daggerboards deployed, the separation was dramatic and immediate.
There’s a subtlety here that goes beyond raw pointing ability. A keeled cat that gets headed by a wind shift tends to stall — it crabs sideways, loses speed, and has to rebuild momentum. A daggerboard boat, by contrast, keeps moving. The sails tell you to bear off a touch, but the boat doesn’t come to a grinding halt. It’s a fundamentally different sailing experience.
The "Emergency Reef" Trick
One of the most surprising revelations from the conversation was Phil’s tip about using the daggerboards as an emergency depowering tool. If you’re sailing upwind and see heavy weather approaching faster than you can reef, simply raising the leeward daggerboard can have roughly the same effect as putting in a first reef. It makes intuitive sense — that board is carrying enormous load, and removing it from the equation instantly reduces the forces on the rig. It’s the kind of practical seamanship knowledge that only comes from years of experience with these boats.
Addressing the Concerns
Every boat show conversation about daggerboards eventually lands on the same two worries: What if I break one? and What about grounding?
On breakage, the Balance approach incorporates a crash box behind each board, designed so the board shears away on hard impact rather than transmitting catastrophic loads into the hull structure. And even if you do lose a board, the redundancy built into a catamaran works in your favor — a single remaining daggerboard still produces better lift than a dual-keel setup. You’re not disabled; you’re degraded, which is a critical distinction for a voyaging boat.
On grounding concerns, the practical advice is straightforward: when navigating shallow waters, raise the boards to the level of your rudders or sail drives. Let those be the first point of contact rather than the boards. And it’s worth noting that rudder damage from a gentle grounding — typically a bent shaft — is often a simpler and cheaper repair than replacing an entire daggerboard.
The Shapes of Lift: Straight, Curved, and Everything In Between
The conversation also touched on the variety of daggerboard geometries available. Straight boards, curved boards, L-shaped foils, T-shaped foils — each represents a different point on the performance-versus-complexity spectrum.
Curved boards, for instance, generate a vertical lift component in addition to lateral resistance. This effectively reduces the boat’s displacement, cutting drag and increasing speed. It’s the same principle behind the foiling America’s Cup boats, just applied in a more moderate, cruising-appropriate way. The trade-off? Curved boards are expensive to build, complicated to haul and service, and eye-wateringly costly to replace — Phil cited a case where replacing a single curved board ran to $100,000, much of which was likely shipping costs for an oversized, oddly shaped crate.
The Balance approach uses straight boards with tapered tips, a plan form that improves hydrodynamic efficiency while keeping the boards practical to manufacture, ship, and replace if necessary. Patrick noted that these tapered boards are designed to be partially deployed at all times — there’s an ideal daggerboard depth for every point of sail, every wind condition, and every maneuvering scenario.
A Little Bit of Foiling for Everyone
Patrick offered a nuanced perspective on the relationship between daggerboards and foiling. Because the boards on most cruising cats are mounted with a slight inward angle (partly to maximize interior volume), they naturally produce a small vertical force component. You won’t fly a hull, but you are, in a technical sense, “foiling a little bit.” That vertical lift reduces displacement, cuts drag, and — perhaps most importantly for cruisers — provides dynamic damping that makes the boat’s motion more comfortable in a seaway.
This is performance in its broadest sense. If a kinder motion allows you to push harder in rough conditions, you’re achieving better passage times not through raw speed but through usable speed. It’s a distinction that matters far more to voyaging sailors than any polar diagram can capture.
The Bottom Line
Phil put it most directly: if a catamaran has daggerboards, it’s a performance catamaran. If it doesn’t, it isn’t. That might sound like a hard line, but the physics and the experience back it up. The good news is that daggerboards aren’t nearly as complicated to live with as their reputation suggests. Raise them, lower them, adjust them — it’s no different in principle from trimming a sail, and the rewards in terms of pointing ability, speed, safety, and pure sailing pleasure are profound.
Next in our series: we dive into Velocity Prediction Programs (VPPs) and polars — the tools designers use to predict and optimize catamaran performance across every condition.
Catamaran Conversations is a collaboration between Balanced Catamarans, Far Yacht Design, and sailing journalist Herb McCormick.
