46 foot Aluminum Modified Oro Wharram Catamaran
Built in 1976, Launched in 1978
We believe that Sanderling is one of only two aluminum Wharram catamarans ever built.
We chose to build in aluminum for several reasons, mainly long life, low maintenance, and strength.
Wharram intended his original designs to be built cheaply and easily by amateurs, and yet to be fully seaworthy. His plywood designs were just that.
However, those plywood boats often had a short life and high maintenance. We wanted something different.
Sanderling is built of 5086 aluminum alloy, which is ideal for marine use.
The hull is 5/32 inch (4 mm) thick. 5086 alloy is strong, easily welded, and very resistant to corrosion in salt water.
Sanderling has been in the ocean since it was launched, 43 years ago. It is bare aluminum, above and below the waterline, and is still in excellent condition.
Corrosion? When 5086 alloy is exposed to seawater, it does not corrode unless there is electrolysis or stray electricity. Electrolysis is easily avoided by ensuring that no metal, other than the 5086 aluminum touches the water. Since the hull is all aluminum, that isn't a problem.
Stray electricity can be a problem in marinas. Using a GFI, and cutting the green shore power wire help. If Sanderling were tied up in a marina, she should have zincs installed on the studs we have put on the bottom.
The bottom line is that Sanderling has been in the water over 40 years, and is still in good shape.
A further advantage of aluminum is that it is easy to survey. We have all heard of wood or fiberglass boats in which a survey missed rot, water infiltration, etc. Surveying an aluminum boat is easy and reliable.
If aluminum is so good, why aren't there more aluminum sailboats? Actually, there are lots of large monohulls made of aluminum. They just aren't noticeable under their white paint.
Aluminum is not common is multihulls because building a medium sized, lightweight boat in aluminum is slow and time-consuming. Sanderling took perhaps three times as long to build as would have been required in plywood or fiberglass.
Other design changes +
Sanderling is far stronger than a standard Wharram plywood design. We haven't regretted that! The hull is extremely strong. The main beams are factory-laminated glulam beams, and were fully pressure treated. The bolts attaching the beams to the hulls are oversized stainless steel.
We didn't like the standard Wharram design in which the cross beams are above the level of the deck. Our deck is flush with the top of the beams, so the entire deck is at the same level.
Sanderling draws about 3 feet (.9 meters). That is more than the standard design, but allows us to carry plenty of gear and stores.
Sanderling anchors from the stern. That is mainly to avoid sailing at anchor, a problem with many boats. It also is convenient when beaching or shore-tying.
Hulls Decks etc +
Aluminum Hulls including cabin sides and roof.
Cabins are in the hulls, no center cabin, one goes outside to get to the other hull. Bimini
tops cover the companionways.
Deck is cedar boards full length of boat, flush decked, beams are under the deck. Deck boards are finished with wax and mineral spirits against rot, but easily replaced.
Deck is below top of cabin roof so the cabin forms a natural boundary for the deck. Not easy to fall overboard. Large deck, 8 feet wide and 40 feet long means lots of space to put dinghys, kayaks, canoes etc. while under way.
It is very easy to pull a dinghy up over the bow beam onto the deck and lash it down. There is lots of space to do this. We often have a 17 ft canoe and a couple of sea kayaks up on the bow.
Hulls joined together with four pressure treated gluelam beams very oversized from original plans. The beams are connected to the hulls with oversized stainless bolts and Wharram standard rubber connections. This allows a small but important flexibility.
Bow and Stern have smaller gluelam beams connecting the hulls, used for anchoring and supporting deck boards and boarding ladder off front.
Sanderling has no bottom paint. We beach her, scrub her with a pressure washer to get the bottom clean.
One could put bottom paint on but we prefer to keep her clean while sailing by beaching and doing an occaisonal light scrub.
Rig & Rigging +
Junk Rig. Similar to Hasler's design, but the sails are rectangular.
Sails are blue polyethylene tarps. Sails are in usable condition, but should probably be replaced fairly
Making a new suit of sails consists of buying two large tarps, putting a multi-layer hem around the edge, and screwing on the battens. Blue tarps work well for junk rig, as the stresses on the sail fabric are very low.
Masts are tapered, free standing island fir trees, cut by us on Stuart Island, WA. They are finished with wax and mineral sprits. Mast steps are 1/4 inch aluminum, 4 foot high by 1 foot square.
Mast steps are anchored with welded aluminum brackets to the beams. Mast beams are very large to support masts, along with fore and aft beams, under the deck, to take sail forces.
Running rigging is inexpensive solid braid nylon rope. On the Junk rig, the loads on running rigging are small.
Junk rig is easy to sail. Halyards and sheets are multi-part purchases, so no winches are needed. Reefing is easily done by lowering the sail by one or more battens.
Masts are easily recoated with wax and mineral spirits from a bosons chair, using running rigging, no need to remove any finish, just put more on.
Steering is by tiller bar, 2 wood laminated rudders, varnished, which kick up when we beach the boat. Rudders are easily removed to store inside when Sanderling is not being used.
There is an tiller pilot.
Engine etc +
Beta Marine 40hp diesel 4 cylinder, installed new in 2010. Runs very well.
The engine is in a pod set into the deck between the hulls. The lid of the pod lifts off, giving access to the engine. No more crawling around in the bilge to do maintenance.
The diesel tanks are hung under the deck, and that means that no diesel or diesel smell is
inside the boat.
The engine is connected to a long drive shaft under the deck, and then to a large prop.
Prop and shaft are lifted out of the water under the deck while sailing.
Electrical & Nav +
Sanderling has complete 110v and 12 v systems, so there are outlets throughout the boat.
Charging is from dual engine mounted alternators, controlled by an external regulator.
2000 watt inverter with large battery charger for shore power charging.
Solar cells provide plenty of power in sunny weather.
Electrical panel in the shop is exposed to show exactly what is happening and where circuits are going, not your usual tangle of wires hidden out of site.
Two Gel 8D batteries powered by solar panels and alternators on the engine.
Radar tower, but radar does not work.
Modern navigation is done with cell phone gps.
Many paper charts of Pacific NW, San Juan Islands are on board, British Columbia and SE Alaska
Cruising guides to these areas.
Ground Tackle +
2 CQR 60 pound anchors and 1 35 pound CQR anchor.
600 feet 3/4 inch anchor line, stored, flaked, under the deck.
400 feet 7/8 inch anchor line, stored, flaked under the deck.
600 feet 3/8 bow tie line on spool reel on bow. Can be stored inside when not in use.
400 feet 3/8 bow tie line on spool reel on bow. Can be stored inside when not in use.
Large, strong cleat for anchoring.
Sanderling anchors from stern.
Sanderling lives on a mooring and has been for 40 years.
Galley, Plumbing etc +
Sanderling is completely plumbed with hot and cold running water.
150 gallon tank capacity fresh water.
Hot water tank heated with engine hot water heat exchanger.
Baseboard hot water heaters heated with engine water, needs connection to the engine.
The Galley or Kitchen as I call it is fully equipped as a kitchen, full double sink, hot and cold running water from pressure pump and regular household faucet, butcher block counter top 48 inches long 20 inches deep.
Cupboard shelves below counter, sink and 4 burner propane stove. Small mixer and blender,110v, can be used when engine is not running. Full size RV Propane oven above stove.
Bench 5 feet long with storage for food behind it and under it (canned goods).
Full set of Faber ware pans and pots for cooking.
Full set of dishes, serving and cooking utensils.
Room with lots of food storage space, microwave, hanging coat closet, clothes line for drying wet clothes.
10 cubic foot fridge-freezer powered by Adler Barber 12v cold machine, work great and has been for 30 years.
Small efficient 110v washing machine for clothes and sheets. Runs off inverter when engine is running.
Note the solar panels by themselves run lights, fridge/freezer, and other misc electricity needs during summer months in the Pacific NW area.
The batteries are kept charged by the solar panels, even when we are not on Sanderling so when we return the batteries are up and can turn on fridge and lights.
Sanderling is fully set up to fabricate and weld aluminum and steel.
Onboard is a spool MIG welding gun.
This is powered by the two 8D batteries, which are connected in series for welding. This gives the 24V DC power which is standard for welding aluminum.
A bottle of compressed argon gas on board is used to allow aluminum welding.
Tools suitable for cutting, drilling, and shaping aluminum are included.
Interior Layout +
Each hull of Sanderling is divided into 5 rooms, three of which have standing head room.
Each of the three main rooms is about 8 feet (2.4 meters) long.
The rooms are divided by bulkheads with 5 foot headroom, which you have to duck under to get from room to room.
Each of the middle 3 cabins on each side has a row of large windows on the outside. They are 1/4 inch tempered glass, in a strong frame.
Port side - from Bow - Bow sleeping room with kneeling head room, one person full length bed, foam mattress, sheets and blankets, quilts included.
Master bed room with kneeling head above the queen sized full bed complete with thermo rest mattresses, sheets and blankets and quilts, with bookshelves on both sides of bed, complete with many books.
Large storage area below bed with hanging clothes area at front of area. Standing heading room in front of bed for getting into the bed with storage shelves beside that area for clothes.
Middle room has desk area and higher table work space. Bench to sit at desk area with extra fold down table. Shelves above 7 foot wood desk area and storage bins below and book shelves with books below that. Work space table has bins below and shelves above.
Next room is the shop with bench space on both sides of aisle. 2 8D batteries, large inverter, runs 110 appliances, assorted tools, complete welding system, runs off the batteries. Lots of spare parts and extra things for repairs, including aluminum.
In the far aft of port side is a small bathroom complete with a tub you can sit in and stretch out your legs. Hot and cold running water and sprayer for sit down shower.
Drains with a bilge pump into sink drain. Sink also has hot and cold water. Toilet is a
Starboard Side - from Bow
Bow sleeping room with kneeling head room, one person full length bed, foam mattress, sheets and blankets, quilts included.
Next is living room, U shaped seating, seats 4 comfortably, foam seats with pretty Guatemalan fabric slipcovers. Book shelves on both sides behind seats, complete with books, cruising guides and many other interesting books. Titanium wood stove and chimney. Plenty of wood storage under the floor in living room. Stereo system with good speakers.
Middle room where companion way is, is the kitchen. It is described above in Galley section. The lower cupboard door flips up to be the kitchen eating table, using the bench opposite the counter to sit on for 2 people. Two more can sit on stools at the ends of the table.
Next is the kitchen storage room with fridge/freezer and its works and many storage shelves.
Last in the starboard stern is a storage room entered from outside. It has the hot water tank in the bottom and long wide shelves, many feet of garden hose to fill fresh water tanks out in the wild from streams, 4 lawn chairs for use on the deck and beach. Propane grill for cookouts, many spare parts and items for repair. Its hatch cover is all aluminum.
The other 3 hatches are lexan plastic, can be latched securely down from inside. (there is
access from inside)
All floors are linoleum, easily cleaned with 110v vacuum cleaner on board. Throw rugs are on board for floors in colder weather. Rugs can be washed in the washing machine.
Bilges are totally dry and great for storage. Middle rooms on both sides contain bladder water tanks, under the floor, 75 gallons on each side, filled from outside on deck.
Most shelves on Sanderling are aluminum. Some are covered with wallpaper or contact
Walls ceilings are painted Styrofoam.
Companion way stairs are carpeted for non skid entrances.
Good, but with a large dent in the port aft gunwale.
Structurally and functionally sound.
Boat details are supplied by the owners & cannot be guaranteed by SBM. You must verify those details personally, or employ a Marine Surveyor before purchase.