Struggling a bit here.
4A - Monograph in praise of round-Britain sailor (8) I have ?G?I?O??
1D - What you will (8) I have ??B?????
3D - Riddell wrote above it (9) I have ??S?????N
16D - Hill woman is gregarious (9) I have C?U?B?B?? - clubbable I suppose but why ?