Fifteen of the caches are at the coordinates given for them. You need to record the number inside the lid of each cache to find the coordinates to a 16th cache (GC6NN4W) that contains a special geocoin for the FTF, featuring something else that Island Bay is famous for.
The coordinates for the 16th cache are South ABo CD.EFG East HIJo KL.MNO, where A is the number inside the lid of River Roads #1 – Dee Street, B is the number inside the lid of River Roads #2 – Tamar Street and so on up to O, which is inside the lid of River Roads #15 – Severn Street.
Medway Street
Medway Street is named after the River Medway in south-east England. It rises in the High Weald, Sussex, and flows through Tonbridge (where the cache owner comes from), Maidstone and the Medway conurbation in Kent before emptying into the Thames Estuary near Sheerness, a total distance of 70 miles or 113 km. About 13 miles (21 km) of the river lies in Sussex, with the remainder being in Kent.
It has a catchment area of 930 square miles (2,409 km2), the largest in southern England after the Thames. A network of smaller streams feed into the main river, which rise from points along the North Downs, the Weald and Ashdown Forest.

The cache
This is a straightforward park ‘n’ grab, but is in a residential area, so please respect the residents’ privacy and be discreet. It’s a very high muggle area due to the adjacent supermarket and vet clinic. It’s on public land, so there’s no need to enter private property. Bring your own pen or pencil.
You are looking for a small red bison-type container.
Do please log a DNF if you can’t find it. There’s no shame in a DNF! This is particularly important, as this is a series of caches in which all need to be active for finders to locate the final cache.