Right, that's what I thought but can you find it in the rulebook?
To steal from Matt, above, and clarify.
Proper Course A course a boat would sail to finish as soon as possible in the absence of the other boats referred to in the rule using the term. A boat has no proper course before her starting signal.
The way the A catters play the defense is, "If you didn't get hit you obviously had time to respond" . The "time in a seamanlike manner" is pretty much open ended.Some of the fastest guys I know get extremely lethargic in that situation.
Was it Phillip, Jake ,or Trey?