I’ve been aboard Exeter a few times when we were looking at the GWS30 reload system. Not deployed on one though.

The batch 1 and 2 42’s were absolutely notorious for being wet ships in a heavy sea. The problem stemmed from the design shrink imposed on the naval architects, as an economy measure, by the Treasury late in the ships design cycle. Sandy Woodward, later of Falklands fame, had the original Sheffield on her pre-commissioning workups in the late 70’s and he made a wonderful comment that, when enquiring into the problem, he found that the bows had more ‘happened’ than actually been ‘designed’!.

The problem was sorted out on the batch3’s with the stretched bows. Nottinghams refit didnt go quite that far!.

The photo is the combination of, as Wanshan accurately noted, a hard turn to starboard and an abnormal swell!.

Why the change of magazine? Is it for adding internal strength?

Even more simple!. That Aussie rock caused the flooding of and extensive damage to the vessels original magazine.

What kind of sonar is it? Hull mounted? (I think previous one was hullmounted right?) or bowmounted?

Sonar 2050 is a bow mounted array developed by Ferranti/Thomson Sintra. Its the same array as fitted to the Type23 and replaces the original Sonar2016.