The Visayan cross-section shows in the stern area a minimally raked flat transom, outboard kick-up rudders (not shown), a very large after deck area, and an effectively invisible aft beam under the broad stern deck area.
When applied to cruising or charter boats the modern stern design arrangement is primarily optimized for style and to a lesser degree performance. Some weight reduction of the hull structure is achieved, which if fully taken advantage of may allow for a leaner hull in the water at the stern and the boat's sailing performance will be moderately improved. It also looks modern (or at least like everybody else these days.).
Also eliminated is the weight of any deck surface between the hulls aft of the after beam. However the problem of how to carry one of the larger dinghies that crusing sailors require must still be resolved. Racers or marina cruisers may be able to sail temporarily without a service dinghy, but you must have one on board when cruising. The frequent result is the weight of the useful deck space eliminated is at least partially returned by the installation of davits or a large swept back "Targa" bar. This bar can provide built in dinghy davits and a support platform for radomes, antennas, and what not, but you cannot walk or lounge on this added bit of windage. We predict this fad, like fins on cars, will eventually fade in favor of more practical, less "styled" elements, such as used on the Visayan arrangement, where we provide multi-purpose useful deck space, and simple lightwight vertical supports for antennas and radomes.
Most modern cruising and charter catamarans with this configuration also have recessed stern platforms and boarding stairs in the transom area. (dotted lines) These became the fashion a decade ago or so, and it seems you can hardly find a boat now without them.
This stern arrangement can provides inconvenience and discomfort however to the cruising catamaran sailor, and even create potential dangers.
Awkward dinghy boarding:
Since the transom corners are sloping forward from the low boarding deck, there is no convenient handhold while making the crossing from the dinghy to the ship. In calm waters or a marina this may be tolerable but in a rough anchorage with the boat pitching even moderately and the dinghy bobbing up and down this is not only just awkward but potentially dangerous. If the transom surface is broad and the stairs are narrow, it can be a real challenge to get aboard. Under these conditions an additional vertical side boarding ladder is essential . This situation was clearly observed after launching our recent project with this type of stern. Even in calm conditions everyone preferred to board on a springy stern netting installed between the hulls, rather than on the stern steps of the hulls.
The Visayan transom is not intended to be a boarding area, so appropriate and safe side- boarding ladders are always in place or available.
Obstructive Vertical Aft beam:
Catamarans require a strong cross beam between the hulls in the stern area. As it is not carrying the mast compression loads the after beam can be smaller than the massive forward beam, but it still remains a significant structural feature of the arrangement of the boat.
By elaborate arrangement of deck levels, helm stations, seats on the beam, winch and traveler track placement, and so on, the designer can make logical use of and somewhat reduce the obstruction caused by the stern cross beam. It almost always leaves a significant change of level however from the external side decks to the interior bridgedeck floor level. In many designs it acts much like a fence to clamber over as one moves about in the stern area of the boat. Usually the area aft of it can be used for nothing but a dinghy on davits. In harbor the after quarter of the boat between the hulls is an unuseable void.
Interestingly the bigger forward beam is frequently less obvious than the after beam, as it provides useful forward deck area, interior bunk or stowage space, and can be pierced in the hulls by doorways. We decided to apply the same functionality to the after beam.
The Visayan aft cross beam has been rotated to a horizontal position and buried in the after deck. Because it is an integral part of the large external deck surface and the interior salon floor/underwing the beam depth can be made quite shallow. We are able to design this depth to be the optimum amount between the aft hull sheer level and the slightly lowered bridge deck level. Generally this is only two very comfortable steps. We usually use the forward portions of the hollow beam for fuel or water tanks, and because it has so much surface area, we can also cut sizeable hatches into other areas of it to provide useful wet locker stowage without compromising it's overall strength. The result is there is no aft "fence", and a large and very useful deck area is created in the stern of the boat from sheer to sheer.
It is necessary to enclose this with stout lifelines of course, and provide as many hand holds as possible for safety when the boat is moving. Some of the stanchions are made removable to allow dinghy stowage on the aft deck when underway, with sufficient deck area still available for operation of winches and general traffic.
Loss of Deck area:
With the modern arrangement as much as 30% of the potentially available bridgedeck surface area has been removed from the boat, and in the raked area aft on the hulls themselves the surface can not be walked on due to the extreme slope. The reduction of bridgedeck area is inconvenient. The loss of hull stern deck area is functionally awkward and can present dangers. We have seen catamaran designs from well regarded designers which have almost no more useable exterior deck surface than a similar sized monohull.
In cold weather sailing or living aboard the interior of the boat is where most of life goes on, and this loss of deck area may not be missed so much, but in the tropics if shade is available life is lived outside as much as possible at the anchorage and even underway.
All of the Visayan catamarans retain the central stern deck area all the way to the transom, and at one gently cambered level from sheer to sheer. At first glance this may appear bulky when looked at in the plan views, but the usefulness and the overall feeling of spaciousness this provides to the boat is immediately appreciated when first stepping aboard.
Kick-up Rudders with Single retractable Centerboard:
We certainly didn't invent kick-up rudders, they are available on many different kind of boats, but you rarely see them on larger cruising catamarans these days, and we think they ought to be there. The world is not yet totally "marinized" and as a cruising sailor you will still find many situations where deliberately beaching the boat for bottom painting or other maintenance will be required. You can expect an occasional beaching situation that wasn't planned too. This "big and shoal" is one of the real advantages of the catamaran configuration, but not if you are sailing with deep spade rudders. As mentioned spade rudders may be slightly more efficient under sail, but cruising "performance" involves practicality in all matters of conducting the overall voyage, and sooner or later, that is going to involve beaching the boat.
The strong Visayan skeg type rudders are designed to easily and fully kick up either after accidentally striking an object while underway or by deliberately being released to swing up. They can be completely removed from the boat by removing just two bolts.
A single well designed centerboard has proven to be very adequate for good cruising sailing performance in the Visayan designs. Minimum interference with hull accommodation is achieved by placing a useful pilot berth and counters over the centerboard case. Only one hull has to be configured to accept the board and we usually have a very spacious "galley down" in the other hull. Our centerboard has been designed to be nearly as efficient as an equivalent high performance daggerboard, but with the added safety of being able to automatically kick up in the event of striking an object or the bottom without damage to the board or the boat. The centerboard control lines are run aft to the cockpit area where they can be quickly released.
Rotating Wing Masts:
Our Visayan designs carry conservative sloop rigs with rotating masts, fully battened mainsails, and furling jibs as standard for ease of handling while cruising. The slightly reduced sail area is handily made up for by the efficient performance of the controllable foil shaped mast. These masts use much less rigging than standard mast plans which reduces windage aloft and expense. Mast rotation is controlled by two sheets led to the cockpit area, and proper use will be quickly learned. For enhanced sailing performance in light to moderate conditions an additional "screecher" can be set free-flying on a "prodder" a-frame from the forebeam in front of the forestay. The rig has now in effect become a cutter sailplan.
The masts are very carefully built in our shop to engineered designs from Barlow Wing of the UK.
If preferred an aluminum non-rotating mast can be installed.
Maximum Natural Ventilation:
The name of the game for comfortable tropical cruising is ventilation, an important feature often overlooked in designs intended mainly for use in colder climates. An otherwise well designed boat, if not properly ventilated, will be a sweaty misery in the tropics.
The forward bridgedeck windows on the larger Visayan designs open wide, but will still seal well when closed, and will safely stand up to the roughest sailing conditions. When fully open they add extra shade to the forward salon and permit the lightest breezes to flow through the entire salon area for maximum comfort. Large deck hatches are installed over the hull cabins, with opening side ports to keep air moving down below as well. Through-out the beams, bunks and storage areas, careful attention is given to ventilation to keep the entire boat fresh and cool. Noisy gensets and air-conditioning are not required on a Visayan catamaran.
Simplified Interior Arrangments:
The interior furniture and appointments have been simply designed and are crafted to enhance the feeling of openness and lightness functionally provided by the generous deck area and ventilation openings. We paint the interior of the boats with the same paint used on the hull and decks for maximum durability, with a modest amount of varnished or colored trim. The result is a seamless, easily cleaned, and maintained interior.
Attractive lines:
Beauty is in the eye of the beholder of course, and we certainly can't claim to be unbiased, but we feel we offer an unaffected design that is functionally attractive without deliberate styling, contrived angles or elaborate paint schemes. The boats have a pleasant blend of traditional appearance suitable to the sea in harmony with their modern multihull character. It has been a genuine pleasure developing the Visayan Series of catamaran designs. Consider the pleasure of owning one.
