Phil, there is NO premium for FTF's, the whistle is just to alert a team at a cache that you are coming. Then they have to finish up and vacate, whether they find the cache on not within 3 minutes. If no one else comes they can wait and go right back after your 3 minutes. The objective is to make sure that each team finds the caches on their own. These caches are spread out so, that we don't expect this to be a big issue, but needed some way to deal with any traffic jams that may develop.