Kudos to Sailormon6. Be aware that racers are indeed use to sailing close to other boats, and if you are on the course they may get real close to you, feeling there is plenty of room.
Know your rules (the COLREGs and Inland Waterway rules, not racing rules). If you are the stand-on vessel then you should be able to do just that. If you are give-way, racers will generally expect you to do so although they won't completely trust you to know what you are doing.
On the boats I have raced with good communication and trust between helm and bow a crossing with inches to spare is not out of the ordinary.
On my own boat, I try to avoid start and finish lines, and turning marks and to pass behind racers on the course.
sail fast, dave