Independent Quixote

[Nical]

Just realised I missed one this morning - and now it's evening, my brain has slowed down.
21 D. Island visible to all with school of whales around it (4) -u-m
I can see 'guam', which I think is an island - if so, what's the significance of 'visible to all with school of whales'?

[vegasmad]

gam (a herd of whales or a social congregation of whalers, especially at sea.) around
u (film rating suitable for everyone to see)

[Nical]

Thanks - that's great. I knew of the 'u' for universal/everyone, but probably spent too long pondering pods and schools for the whales!