From a judging stand point you need to be mindful of parking, entry, and exit from the test area. Try not to have a whole lot of moving around at the line. If you hav ea BIG entry test and it takes 30 seconds per dog to move from a marking line to a blind line you're gonna waste a lot of time just moving the dog from line to line. If you have to wait on vehicles entering and exiting the test area and disrupting the test then you're gonna waste bunch more time on that. These little things add up quickly if you have to multiply 30 seconds to a minute per dog and you have 55 dogs! Long swims for no real apparent reason. If you don't need'em don't use'em, other wise your just watching dogs swim all day long. As far as BIG entries go be mindful of how much time it takes one dog to complete a test. You may have a very good test but simply takes too long to complete it. Save those setups for weekends when the entries are lower and you have time to play! I'm not saying test up test to drop dogs. Just be mindful of the time concumption each setup requires.
And a good well trained marshal are worth their weight in gold!