I found this very easy indeed at first with all but 3 answers written in after only 9 mins. A little slower getting those last 3.

Solving time: 14 mins

Notes on some clues below: happy to explain others if asked.

* = anagram

ACROSS

8 SOLE One of the sea areas used in the Shipping Forecast

9 MOUSSE How a Scot might pronounce ‘mouse’, I think

18 DI’S T (R) AUGHT R being one of the three Rs

22 LAV (END) ER

DOWN

1 I’M POSING

11 ERATOSTHENES (So earnest the)* Greek mathematician of old.