[1] The Inner Sound is the location of BUTEC, a Royal Navy submarine sensor and emissions range.

[2] The Inner Sound includes the deepest section of the UK's territorial waters, with a maximum depth of 324 metres (1,063 feet).

[3] A dive to examine the deeper trench found the bottom to be made up of bioturbated mud, with a steep slope towards the west of up to 60°.

[4] In 2020, over a hundred eggs belonging to the critically endangered flapper skate were discovered in the strait.

One major excavation also took place at Sand which was a shell midden dating to the early-mid seventh millennium BC.