I have recently been using a half G5RV; very effective for medium distance communications and occasionally Dx.

I recently tried to set up a CW practise sked into north Devon on 40m (7.0 mhz), signals were very weak RST 218 sent at 100 watts with QRM and QSB. Seems this may be the skip zone.
The answer could be NVIS antennas which could also give an opportunity for HF SSB club net, and more contacts in the uk, WAB and SOTA .

Seems worthy of an experiment so Rex and myself will try some experiments as weather allows.

Educational notes:-
https://cdn.rohde-schwarz.com/pws/campaigns/rsa/Rohde-Schwarz_Understanding-NVIS_v1.1.pdf

You tube:-

Let me know if you set up and NVIS antenna and want to try some experiments

John (M0hfh)