The Quote is from English poet John Donne.
In its very simplest and most prosaic sense it means we all depend on one another and in a way all our actions affect others.
In the case of this series of caches, You may need to enlist the help of others to get to the hide to look. Although it may not appear so, during low water levels, there is indeed an island here, and as such it is indicated so on various topographical maps.
Findable in winter, but you may not want to trust the ice.
Watch your step, Be safe and above all . . . Have fun !!!
* * * * Congratulations to ProfesserLeisure & Awhip80 for the Early Bird Co - F-T-F * * * *