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.
Humber Street
Humber Street is named after the Humber, a large tidal estuary on the east coast of Northern England. It is formed at Trent Falls, Faxfleet, by the confluence of the tidal rivers Ouse and Trent. From here to the North Sea, it forms part of the boundary between the East Riding of Yorkshire on the north bank and North Lincolnshire and North East Lincolnshire on the south bank. Although the Humber is an estuary from the point at which it is formed, many maps show it as the River Humber.
Below Trent Falls, the Humber passes the junction with the Market Weighton Canal on the north shore, the confluence of the River Ancholme on the south shore; between North Ferriby and South Ferriby and under the Humber Bridge; between Barton-upon-Humber on the south bank and Kingston upon Hull on the north bank (where the River Hull joins), then meets the North Sea between Cleethorpes on the Lincolnshire side and the long and thin (but rapidly changing) headland of Spurn Head to the north.

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 on public land, so there’s no need to enter any private property. Bring your own pen or pencil.
You are looking for a black camoed Eclipse mint tin. Please replace it exactly as you found it and 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.