Great Bluewater Sailboats ... Full Keel Cutter
All smiles aboard his brand new custom Falmouth Cutter 34 by Lyall Hess; owner, Gunnar Strobel receives in-depth hands-on coaching and consulting from Paul Exner during Moon Raven’s maiden 9-day Bluewater Sea Trial in the Pacific Northwest.
Despite the contemporary view that full keel vessels are heavy and slow, I respectfully disagree. In my opinion, the full keel hull shape will always prove an awesome vessel to go to sea in … these naturally harmonious designs will stand the test of time (mark my words)!
There’s a harmony captured between a designer’s understanding of the full keel and the natural hydraulic properties of the sea; this marriage between tradition and the physical principles of science is no accident, it’s a natural aesthetic transcending post-industrialized changes to popular-design spanning more than 100 years of seafaring history that’s allowed us to sail over the horizon reliably and safely, especially while burdened with cruising gear, provisions, and dreams.
The inaugural build of the Bristol Channel Cutter 28 constructed at Cape George Marine Works in Port Townsend, WA … a classic bluewater specialist … a vessel to go anywhere by sail.
Natural selection gave us the anatomical-form embodied by sea mammals who carry their shape for life! Some naval designers have gained deep understanding of that shape and realize that a floating vessel can also mirror it to support human life on lengthy voyages; and guess what, the full keel vessel created in likeness to sea mammals ARE fast designs … just like an Orca blasting with rapid precision toward her prey.
It’s the cutter rig which is necessary to propel the full keel hull. The trim between a full keel hull and cutter sail plan will create harmony and efficiency with the sea unlike any other design, but it’s not simple to attain. The trade-off to a great symphony should not diminish it to the lowest common denominator … full rigged cutters are a bluewater specialist vessel—they are not easy to sail. However, they provide a vast-range of possible sail combinations to convey aerodynamic-potential to a hull engaged in common oceanic sea-states being thrown at a small vessel and crew trying to cross an ocean—characteristics that make the vessel capable and worthy of serious consideration as a live-aboard passage maker.
“With Knowledge, practice, and experience, the safest and most enjoyable passages are made aboard full keel cutters”
Misunderstood … The value of the cutter / full keel combo will be under appreciated and over simplified in discussion by sailors who have little experience in these vessels. The essence of the cutter rig is to add fore-end power to a hull designed with a full bow (which in turn can carry weight); the boat needs the power forward, along its length to drive it against common offshore sea-states; this is no different from what naval evolution produced aboard heavy displacement sloops of the 1970s when they flew overlapping Genoa-sails to improve their performance which was important mostly in sloop sailboat racing.
The Swan 48, designed by Sparkman & Stephens … a heavy displacement sloop with a “full” forward section, like her full keel predecessors. She requires a large genoa to drive her to windward. One of the early hybrid-designs to capitalize on the popularity of the I.O.R. rating system (International Offshore Rule, circa 1970-1983) while calling itself a performance-cruiser. The boat is so powerful that it proves quite unwieldy offshore for most short-handed crews crossing oceans today.
One common statement made by a sailor with poor-to-zero experience with full keel cutters is: “Simply strike the yankee-sail, and sail under staysail and mainsail when it blows.” This statement rarely presents itself true if you seek the complete advantage of the full keel cutter rig … there’s so much more to the interaction between the yankee-sail and stay-sail than meets the eye. The only time I’d accept such a statement as plausible for offshore sailing is when fatigue is a factor in the decision to simply strike the yankee-sail in a blow; however, it must be absolutely understood that in many cases such a vessel will NOT retain sufficient power to get her through a sea-state and must be born-off to gain power or else such an under-trimmed vessel will wallow in misery.
Island Packet 440 cutter employs the Hoyt Jib Boom which is much more than a self-tacking jib! This cool design by Garry Hoyt revolutionized the stay-sail and is effectively implemented as standard equipment aboard Island Packet yachts or retro-fitted aboard other yacht designs. The Hoyt Jib Boom effectively negates the need for deck tracks for the staysail; instead, the “jib-outhaul” allows for a full configuration of stay-sail twist settings, with one self-tacking jib sheet. The versatility of this design greatly simplifies the operation of a 3rd sail for the cutter-rig, and provides more flexibility to match sail trim with sea states.
Athough, I have completely stricken the yankee in a blow (staysail too sometimes, leaving just a triple-reefed mainsail to employ the fore-reaching technique in a storm), the increased aerodynamic power becomes so HIGH (apparent-wind velocity squared) that falling-off to power-through waves will generate so much additional force (increased boat and apparent-wind speed) that sailing under the massive additional force on the sail plan truly overpowers the vessel and requires heightened diligence on the helm … negating in practice the over-simplified view of “simply striking the yankee-sail in a blow.”
The more probable scenario which showcases the advantage of the full keel cutter is where the mainsail and staysail are optimally trimmed to compliment one another to bring the full keel to max sailing efficiency, but the yankee remains under-trimmed by 10-25% as we sail along often under wind vane autopilot. This strategy is in preparation to handle sea-conditions that promote a hull’s propensity for yaw to leeward—it’s at these moments the main and staysail’s efficiency become somewhat stalled, but the under-trimmed yankee is now fully powered to enable latent aerodynamic force needed to accelerate the hull so the wind vane (or observant helms person) can bring the boat on-the-wind where the complimentary trim between mainsail and staysail can once again put the boat back into its groove, and on course! … This is a repeatable and proven method to dial-in a bluewater cutter rig vessel in common ocean sailing conditions.
TEST SAIL the Full Keel Cutter in Heavy Weather
It’s important to understand that the full keel hull craves sail power! Because of this, it’s extremely important for the vessel to be equipped with appropriately sized and shaped sails. The challenge for the cutter crew is to optimize three sails where each sail becomes more manageable in its size and weight relative to sloops with two sails that would be larger and heavier to propel a similar hull.
Cape George Cutter 31 (SV Solstice: co-designed, built, and owned by Paul Exner) is sailed under asymmetric spinnaker along the Pacific coast of Central America, notorious for light winds. Here the spinnaker (designed by Pat Considine of UK Sailmakers, Chicago) is flown expertly from the ATN Tacker; in addition, the stay-sail is used in conjunction with a full mainsail to propel the SV Solstice swiftly in light wind.
From personal experience I will say that the art of sailing has been vastly fruitful while figuring out how to optimize the full keel cutter offshore; I relish the challenge to optimize the aero/hydrodynamic components. I’ve never felt safer nor had more fun sailing any other small boat design in the open ocean. The common sea state served-up by Neptune offshore is always complex (for all intense and purpose), and that translates to six identifiable types of motion for a hull to experience at sea, which must be harmonized with the vessels sail plan. The six types of motion are: 1) roll; 2) yaw; 3) pitch; 4) surge; 5) sway; 6) heave. The cutter sail plan, driving the full keel hull, truly offers the most customizable blend of characteristics to harness the dynamic realm of ocean sailing.
The SV Solstice (Cape George Cutter 31), co-designed, built, and owned by Paul Exner is sailing under full cutter rig in the Antigua Classic Yacht Regatta. Anyone going to sea is a specialist, and their boats don’t need to be oversimplified for the sake of simplicity; instead, serious offshore boats are tunable and configurable to harmonize with a wide variety of ocean sailing conditions. If you’re looking to get across the ocean as fast as possible with high expense, why not own a jet airplane; otherwise, the full keel cutter is a great option for bluewater sailing.
Some sailors believe the notion that the full keel will “track” a straighter course than designs with shorter keels, and I’ve found this idea to be somewhat true; although ALL boats yaw a lot in the ocean. In fact, I may argue that full keeled vessels “track” worse than other designs as there’s a larger underwater profile for overtaking waves to push around. However in following seas, modern yacht-designs like Hanse, Bavaria, and others I’ve sailed recently prove squirrely-beasts that over-taxed their auto-pilots even with their MAX Response Sensitivity selected because these “modern” yacht designs and electronic systems still could not keep the yacht on track due to their relatively small “performance” rudders, and short keels prone to heavy yaw. After my experience with these “modern” designs in bluewater, it’s certainly arguable that full keels “track a straighter course,” even off the wind with following seas.
What is true from my experience with full keel designs is that they’re more likely to sail themselves while keeping in the groove compared to designs with shorter keels. Numerous times I’ve trimmed the sails for a particular groove and let the tiller do what it wants (without autopilot) and the boat sails the course I set. Since the full keel carries a larger proportion of weight in her ends (higher prismatic coefficient) they can certainly carry more sail area distributed over her length, hence the cutter rig with sails flown from the bow and bowsprit with mast positioned more forward in the hull compared to sloops allows for generally longer booms and larger mainsails. The entry and exit of the bow and stern respectively make for a kindlier hull that knifes into oncoming waves rather than “pound” like modern flat-bottomed hulls do; although this characteristic does make full keel hulls more susceptible to pitching which ultimately slows boat speed and momentum—another reason “more” sail area is required along the length of a full keel cutter happier on broader tacking angles to give the full keel vessel the raw punch to drive through waves.
Paul Exner sailing closehauled in the Caribbean Sea aboard his SV Solstice which he co-designed and built from a bare Cape George 31 hull.
Boats don’t need to be easy to sail in order to go to sea; anyone going to sea is a specialist anyway, and why not sail a boat that’s interesting to optimize, and with sufficient “gearing” to make a harmonious interaction with the bluewater that offshore sailors sought in the first place! If you’re looking to get across the ocean as fast as possible with high-expense, why not own a jet airplane? If you truly wish to cross oceans and sail the bluewater with freedom and self-sufficiency then sail a bluewater specialist vessel … go to sea aboard a full keel cutter rig.