If you're driving, you can reach Isle of Wight by taking the A3(M) from London and then following signs for Portsmouth. From there, take the ferry from Portsmouth to Isle of Wight, which takes about 45 minutes. Alternatively, you can take the M27 from London and then exit onto the A3020, which will take you straight to the ferry terminal.
If you're traveling by train, you can take a train from London to Portsmouth Harbour, where you can then catch the ferry to Isle of Wight. You can also take a train to Southampton and then transfer to a train that will take you directly to the ferry terminal in Southampton. The ferry ride to Isle of Wight takes about 45 minutes.
If you're already in the area, you can catch a direct ferry from Lymington or Southsea to Isle of Wight. Lymington is around an hour's drive from Southampton and is a quaint Georgian market town, while Southsea is a seaside resort located in Portsmouth.
If traveling from the West Country, a good option would be taking a ferry from Portsmouth to Cowes. However, if you're traveling from the North of the country or Wales, a train to Bristol and then a ferry to Cowes would be a good idea.
The closest airport to the Isle of Wight is Southampton Airport, which is approximately 20 miles away across the Solent.
One suggested route is to catch a train from Southampton Airport Parkway to Southampton Central, and then catch the Southampton to West Cowes ferry to the Isle of Wight. Alternatively, you can arrange a taxi or take a bus service from Southampton Airport to one of the ferry ports on the mainland and catch a ferry to the Isle of Wight from there.