Hi Christian and C_I
I'm not sure all OB CI casks are stored on site. According to Andrew Jefford (in Peat, Smoke and Spirit), the amount of CI casks is 3000 and falling. On the other hand the amount of Lagavulin casks is 2000 and rising.
It seems that Diageo has the smallest warehouse capacity on Islay: 5000 at CI, 7000 each at Lagavulin and Port Ellen.
For the two Islay distilleries having the highest production, they just have to tanker most of it away.
And given that they have enormous warehouse capacity on mainland Scotland, I figure that makes sense for them to do so. They even abandonned their warehouses in Campbeltown
According to same book, their cask policy now is, that it makes no difference where the spirit is maturing. Well it would be - wouldn't it
Some people can find salt and sea-air in the nose of CI. Wonder where the sea-air is coming from