Sketches of a 21ft tacking outrigger

This is a design for a 21ft tacking outrigger. Hull beam is just over 1m

Freeboard is generous at 46cm at 300kg displacement. There is a 6ft 5" berth forward with entry via a large pivoting hatch. Behind this there is a bench that provides the modopint of the boat. This bench is made up of two full width bulkheads which aid in giving rigidity to the boat. It also contains a daggerboard of generous area. This bench can be used as a seat with the occupants sitting facing aft.

Behind the bench is a large uncluttered cockpit where two people may sit.

The rig is a schooner sprit, with identical mast and sails fore and aft. This allows for easy replacement of damaged parts. The rig can be taken down and layed on the crossbeans with great ease. A spare mast and sails can be placed at the same spot. Having two small masts instead of one large mast allows the rig to be taken down at sea by one person easily. Time taken to get the boat ready for the water is reduced compared with a stayed rig.

Both masts and the daggerboard have a lot of bury to support the unstayed masts and the loads on the board.

The cockpit floor is above the waterline so as to be self draining. Large buoyancy compartments are placed under the floor and fore and aft. Gear may be placed in the cabin when daysailing to assist with trim, at night when sleeping in the cabin it could then be placed in the cockpit and lashed securely.

Storage compartments are at the stern, in the center bench either side of the daggerboard. The space underneath the cabin floor could in theory be used for storage if desired. The bow compartment I feel is best left as a buoyancy reserve with no hatch access.

This is a 19ft design which is smaller and lighter. It is shown to demonstrate that it is possible to combine a separate cabin and cockpit on a 19ft length. Some big issues with attempting this is where to place the masts, a really big issue if unstayed masts are desired, and secondly where to place the board. This design places the board aft, but attempts to compensate for this by only having a small mast forward. This design has a degree of redundancy to it, as the rig for one mast can be used on the the other, though a reef may well be required.

A hullform file of this sketch is available. If the outrigger still has the center of lateral resistance too far aft, it is possible to lower the front rig, or deepen the forefoot.

The above design appears sound and valid. However there may be a desire to combine the central area into a dual day cockpit and night time berth. This has the advantages that the occupants are always near the center of the boat and in the position where seaway motion is felt least. To achieve both an open cockpit and a sheltered cabin on the same space it ought be possible to have hinged cabin sides that lay flat when day sailing, and then hinge up to protect the occupants from water and wind during storms and at night. The cabin roof itself could be a tarpaulan or plywood again if a double hinge is used. This mechanism is described below

One more option of obtaining an unobstructed center section of a small boat is to use two daggerboards. This has been done previosuly. The downside would be more complication in building 2 boards and 2 cases. Additionally board efficiency may be reduced. However the upside is that it completely frees up the center of the boat. Additionally each board can be adjusted in height to achieve good CLR-CE balance.