The
Fortress is a great
anchor, but unless it''s practical to "dive" the
anchor (& hand set), not great in Grass. Grass is tough!
I''ve used both 35#
Delta & 22# Bruce (as well as FX23) on my C&C29, and found the
Delta to be adequate in Grass (tho'' I always dive my
anchors if uncertain).
A 22 Lb (about 10 kg)
DELTA is roughly equivilent to your FX16, but neither is a great storm
anchor for your C&C30 (I''d prefer 1 size up - FX23 & 35#
Delta).
The Bruce (like most
anchors) does poorly in Grass.
Regards & thanx to good boat neighbours

,
Gord