Tad,
Do you have our book, "Sailing Drills"? Some of the most important skills for racing are boat-handling, starts, and mark roundings, and there are drills in there that you can do alone to improve all those skills. All you need is a few marks, and you can make those out of gallon milk or water jugs and spray paint them orange on the INSIDE. Use big grapefruit bags full of rocks as anchors.

Plus, you could spend hours perfecting starting techniques by just putting out two marks for a starting line and practicing how to find the favored end, time the length of the line, get a transit in both directions, hold your position on the line, or get your timing down for doing a fast approach to the line.

One really good drill is setting out a mark (or using somebody's crab pot float) and trying to stop your boat by the mark and keep it there. It's more frustrating than a video game, but really good boat-handling practice.

In fact, you can even practice your start timing when you are driving your car. I have heard that Dennis Connor is an expert on timing his approach to the starting line and he practices on the freeway by estimating how long it is going to take him to get to an overpass.