On our squib (105) we have spent a lot of time optimizing its performance legally by just doing a few simple things...

Firstly we went to work on the hull. We wet and dried the hull and keel right the way back to within an inch of their lives with 600 grade wet and dry... This allowed us to obtain a super smooth finish therefore allowing us to fully focus on the sailing knowing we could be the only variables on the boat slowing it down. Once this was done the hull is left as it is. However, the keel has to have more work done. As you are all too aware the keels on squibs rust and there seems to be no real cure for this. What we do on keel is paint the keel with VC Tar epoxy primer this is a self leveling paint so it cures with an ultra smooth finish but this is not enough to stop all the rust... The join between the hull and keel will still rust so we add an extra layer of zinc based primer (Ku-rust). This does not stop the rust completely it means before each event we sand back the small amount of rust starts to show and apply another coat...

We also have made sure the rudder and keel are aligned and the rudder is down to weight and as stiff as possible...

We make sure we keep our weight around the 24/25 stone (combined) mark as we believe that this is about optimum for the squib... Making sure when the wind is light that the helm and crew are as far forward as possible in the boat (right over the keel). If you look at a squib when it is out of the water you will realize how far forward the keel is mounted compared to the cockpit so this will give you a good clue as to how far forward to sit.

We were using a Holt canapus mast section and were very happy with it unfortunately is got snapped at the nationals so we are currently sailing with a super spar mast. We believe you will be fast enough with either of these mast sections as these are what all the top boats use...

The most important modification we have made in our opinion is where our shroud plates were positioned. When dead running in a squib you have your boom as far out as possible, touching the shroud wires, this restricts how far you can let the boom out. We measured our shrouds and they were 50mm to far back in the boat and also one was different to the other once this was corrected we felt we had found an extra gear downwind thus opening up many tactical options...

All of the above points are extremely important they do make a lot of difference if you do have the time to make any of these changes I would strongly recommend doing so!