The first thing you want to do is drop the swing keel or centerboard. If that is not down, you will slide sideways and have no or little windward progress. The O'Day 222's mainsail is big, as you pointed out and so should be fairly balanced by itself, but you will have better windward performance if you use the right size headsail for the wind conditions. Based on your drawing you should be able to put the sails up without the wind having much affect on them (let them flog) and then you can climb on board fall off, trim the sails to close hauled and sail away from the dock. If you put the at the end of the dock so you have a beam reach, you will not have as much control and you might not get enough boat speed up so that you can tack before you start mowing down docks. In your drawing, your boat is nearly at a port close reach with the winds coming from where they are and so you can hop on, trim your sails and sail out into the lake on a port tack. If you happen to start sliding to starboard on your port tack, putting you at risk to hit the docks, then you can tack away to starboard. Just remember you have to establish some boat speed in order to tack. So, when you let go of the dock the first thing you need to do is get some boat speed going even if you are heading toward disaster. With boat speed you can quickly tack and avoid disaster. After tacking onto to starboard you will be home free and will be able to just sail out into the lake.
