Does anyone know London to Portsmouth cycle route that avoids A Roads and Motorways?

I would like to cycle from London to Portsmouth in order to go on a camping and cycling holiday in the Isle of Wight. I was rather hoping that someone may be able to provide me with a scenic route which avoids A. Roads like the A3 or motorways. I am looking more for B-Roads and cycle tracks etc. I have looked on the internet but to no avail. I need the advice of a more experienced cyclist who has already undertaken this endeavour. Duration and speed would be good to know also. Please don’t reply with any links for videos they never work. Thankyou.