I'd recommend Morn Hill CC site literally just off the M3 at Winchester. It's about 30 - 45 minutes from IOW ferries at Southampton. This site will also serve you well if you're sailing from Lymington to Yarmouth.
If you're going from Portsmouth to Fishbourne you may like to consider Rookesbury Park CC site at Wickham, just outside Fareham. This is only about 30 minutes from the ferry.
Don't consider the service areas at Fleet or Winchester. Personally I don't think they're very nice places and certainly not in the same league as the CC sites.
Vic
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