I learned about radar assisted collision my first time underway using a faulty set. The bearing was somehow skewed 90 degrees from actual course. Instead of heading upriver we were quickly headed for an allision with the end of a dock!

Chief Chaos definitions:
1. Illusion - when it looks like something is taking place that isn't.
2. Allision - When a underway (moving) object strikes a non-moving object (not a sandbar, bank, or otherwise natural part of the waterbody).
3. Collision - When two underway objects (vessels) strike each other.
4. Allusion/Collusion - When it looks like a moving object or two moving objects are about to hit each other (otherwise known as "time to clean the underware!)