Harbour Seals often haul themselves out of the water to rest, this uncomfortable rock wouldn’t be my first choice though:

Planking Harbour Seal - Holyrood

Planking Harbour Seal – Holyrood

To me, these cushy rocks looked a lot more inviting, and evidently to these seals too:

Harbour Seals on land - Holyrood

Harbour Seals on land – Holyrood