Just had a look at the JAR-OPS 3 Manual.
The relevant section (JAR-OPS 3.295) is quite a bit more detailed.
The get out clause is stated at 3.295(c)(2) which reads (c)"For a flight to be conducted in accordance with the Instrument Flight Rules or when flying VFR and navigating by means other than by reference to visual landmarks, the commander shall specify at least one alternate in the operational flight plan unless:" (2)"The heliport of intended landing is isolated and no alternate is available. A Point of No return (PNR) shall be determined."
It then goes on do define off shore alternate options.
Would be quite happy to copy and mail the whole section to you if you want to compare notes!