I thought I was doing so well but I'm stuck on the last three!
18A 'Current concern being weak'(6)
24A 'Row onto sand, finding port'(7)
19D 'Building where virgin mother cradles Jesus, say.'
Please help me, someone.
20A - you are looking for a word meaning "row" as in "loud racket" which is preceded by a sand feature. The answer is a port in the southern hemisphere.