This is the bonus cache for the Boathouse Row Adventure Lab. Needless to say, there is no cache at this location, and you'll get wet if you go there unless you're in a boat. You will get the coordinates you need by completing the Adventure Lab.
Boathouse Row is a busy area, but we've tried to place the cache in an area less frequented by muggles. Still, be wary of passers-by and, if crossing a street, please be alert for traffic.
We recommend doing this during daylight hours only. Bring your own pen; no credit without your signature.