Very small container, with room for logbook only. Bring you own pen or pencil.
At the listed coordinates you will find a sign post listing the flood levels over the years. Using the top sign, 1936 flood level number, add it to .549 for N42 02,XXX. Add .509 to flood level number for W72 35.YYY. There my be alot of muggles at times so pretend to study the wildlife while you wait.
Container is a bison tube.
You can park near the final and I could see it from my car!
See my log on 12/12/15 for a picture of where the first stage sends you.