My wife and I helped pioneer this ride when it was a BikeWeek event co-ordinated by the local Councils.
The route has changed , but is roughly...
Gosport (Bay House School) to Stokes Bay and along the front to the Gosport Ferry.
Cross to Portsmouth and along the sea front to Eastney and the Hayling Island Ferry.
Pick up the Hayling Billy Trail and follow this to Havant, than via Badhampton and along the crest of Portsdown Hill, before descending into Fareham.
From Fareham via Stubbington and back to Gosport.
Good ride, with a long ascent from Bedhampton, and spectacular views from the top if the weather is good.