Sound advice duly noted. I have an imc and 40hours or so on instruments around uk. I am not planning any very long water crossings but as dover - cap gris nez is about my limit at the moment with a single it will be good to be able to just take a slightly more direct route cross water.
I planned some routes to Norway last year and even the shorter sea crossings from denmark to sweden or norway where rather longer than I liked the look of. In the end the weather forced us to fly south to spain so it was not an issue.
I fly with a more experienced PPL on all our long trips so there is always someone to help with the workload.
Point taken about VHF Nav Aids and low level crossings. Decided PPL-IR would come next after MER !