Flat Earth kayak sail, it has an other interesting addition.. Note the central cord and cleat...
...forward fin for upwind paddle sailing.The fin is 30cm long and measures 11cm fore and aft at its mid length point. The fin is stiff but is cut from a flat plate of carbon fibre composite. It is pulled down by elastic and raised by the cord on deck. It will autoretract if you hit an obstruction. The fin box slot is 49cm long and will obviously increase turbulence.
The fin box is grp and is moulded into the forward bulkhead so it is very stiff. It does add to the weight of the kayak.
I then put the forward fin fully down for the third and fourth tacks. From experiments with the bigger Cetus HV fitted with a smaller Karitek forward fin last year, I expected to paddle sail up wind with just the forward fin down and the skeg up. However, the balance point is different and as soon as I put the large forward fin down the kayak luffed up into the wind but this was easily corrected by putting the skeg fully down. I now found I was paddling 45 degrees to the wind with a 90 degrees tacking angle. This is the same as a Laser dinghy which was tacking alongside. Despite pointing 15 degrees higher into the wind my forward speed remained the same at a steady 7.8 km/hr. I also found it was easier to balance against the F4-5 wind with less strain on my core muscles.
Pros and cons:
The P&H forward fin is highly effective in improving a short kayak's upwind performance. It is very easy to deploy and retract and when fully down the sailing angle can be easily controlled by varying how much skeg is deployed at the stern. I found it easier to balance and control the sail upwind when using the forward fin. On the down side it adds cost, weight, water resistance and another control line. You do not need a forward fin to have a lot of fun downwind paddle sailing the Aries 155. Lastly I found longer kayaks such as the Cetus MV will already paddle sail upwind at 45 degrees to the wind without a forward fin, though these kayaks are less fun down wind than the Aries 155.If you want to add a forward fin to an existing kayak then Kari-tek will be able to supply/fit a slightly smaller one which I found worked very well last year.
In conclusion, I found the P&H Aries 155 with forward fin to be the most versatile and fun sea kayak for paddle sailing which I have yet tried. Upwind performance over the standard kayak is markedly improved. Lastly the pillar box red metallic looks fantastic in the sunshine!