When you are racing a lightweight dinghy, the boats typically sit luffing near the starting line for quite a while before the start. Then the key is to trim in and get going at the right time.
Instead of sitting so your bow is even with all the other bows, hang back 1/3 or 1/2 of a boatlength. This way you will have more room to trim in and go. You can accelerate a couple seconds earlier than the boats on either side of you, which gives you at least two advantages: 1) you won't have to bear off so much to accelerate so you can maintain more of a gap on your leeward side; and 2) if your timing is good you will be going a little faster than the boats that were sitting with their bows very close to the starting line.
This bow-back position is OK because it still allows you to hold your position on the line just as easily as being half a length farther forward. But you have to be careful that you don't accelerate too late – you want to be at least even with the boats to windward and leeward.