Lets use our common sence here gents.
Yes the Solent can be hazerdous, it can get foggy, blow up a hoolie and not be a very nice place. Throw into the mix a failed engine or something and people can lose lives like any other coastal area. The Solent can be a very lonely place even if it is considered to be busy most times. At least you're within easy contact with the services.
But 2 litres of water rations, EPIRBs, liferafts etc etc aren't really needed in day to day cruising around these areas, but if you want to carry these items that's fine.
Doing some cross Channel cruising, I would suggest safety in numbers as the biggest safety factor for the rare trip. However if you do this regularly by yourself then EPIRBs etc would be a wise choice IMHO .
It's really all about risk assesment. You can never have enough gear on board.
Looks Slow but is Fast
Member of the ebay Blue RIB cover club.