Major Tom

The Opti has a single skin laminate on the sides and gunnels. Your pic clearly shows that the resin in the impact area has shattered and if you push a blunt hard object onto the damaged area you will see that it is soft. Is the damage also visible on the insise of the boat?
If the damage is visible on the inside I would tape up a rectangle about 100 by 50 mm on the inside corner, sand it well and put 2 layers of the thinnest lightest glass cloth you can find cut to about 80 by 40 on the patch. I would cut one of the layers at 45 deg to the other one. Use polyester or vinyl ester resin. A piece of peel ply over the laminate will make finishing easier.
On the outside you need to remove about half the thickness of the damaged laminate, making sure that the area is nicely tapered outwards from the damage.i would recommend putting enough cloth on so the repair is proud of the surrounding area. I would also first force as much resin into the damaged laminate as possible to try to rebond to existing fibres together, then thicken up some resin with cotton flocks to make a glue like paste and screed a thin layer over the existing laminate before putting the repair laminate on, do this all wet on wet. One everything has cured carefully sand the repair down so it is about .5 mm below the surrounding gelcoat and then follow Fred's advice above. On the inside, give a light sand then tape up and brush a thin layer of gel over the repair, add wax solution to the gal and it will cure properly with no tackiness.

By the time you have bought spars, a sail, foils, tiller and extension, vang, out haul and Cunningham fittings, dolley and cover and sheets you will be better of buying new boats!

Another shocking start for Webber, how many times has he ad a good start in he last year? Monaco will be interesting if the slow cars end up on pole and hold the faster race trim cars up.

The concern with using a more vertical rudder is that you won't feel the helm generated by poor trim and sail set and you will be sailing with a bigger angle of attack on the rudder blade all the time. This could result in more frequent stalling of the rudder, especially upwind, leading to getting stuck in irons more often.

The optimum weight for a 4.7 is 62kg and for a radial 68 to 72 kg.