Maraya, the first of the M series was designed with relatively deep fixed keels as the owner’s preference, mainly to achieve good windward performance without the complication of daggerboards and the associated control systems.

For the Oasis design shallow draft was a high priority in the design brief, preferably no more than about 1.3 meters draught, and if we limited the rudder to the same depth then the keel would provide good protection for the rudder in case of a grounding.

On getting down to the specifics of the design it turned out that to achieve this I would have to use a rudder blade of significantly lower aspect ratio than I would normally use.

I was able to improve on the situation by moving the rudder further aft and adding another 150mm to the keel draught. To optimise the efficiency of the keel I put a hollow in the keel planform, making the keel waterlines finer at the top than bottom thereby helping to promote undisturbed flow over the keel surface and minimising tip loss. The keel form will be further optimized by adding an end plate to the bottom. 

Daggerboards are an option for the Maraya, and Maniche models in the M series

If the helm is aft, or if it is set low behind the cabin bulkhead then you want the organizers and winches down at deck level. If the winches are higher than about waist level then the ergonomics are terrible, and if you need to lead most of the control lines down to the deck from the cabin top then you have more hardware, more friction in the lines and more potential for clutter.

So ideally decisions about the helm station design and the mast position need to be made together to be ergonomically effective and efficient in operation.

While Maraya had the mast on deck, two factors have influenced our thinking toward a preference for placing the mast on the cabin top for the M Series cats. The first is the raised helm station which makes it relatively simple to lead halyards and sheet lines directly from the mast base to the winches immediately forward of the helm station with a minimum of hardware required for redirecting the lines.