From Wikitravel

The modern Seven Sisters Ferry, leaving Newhaven for Dieppe

Major airports and ferry routes (some are missing)

• Dover to Dunkirk (Dunkerque), France; 1:45 hours Norfolk Line
  
• Dover to Calais, France; 90 minutes Seafrance & P&O Ferries
• Newhaven to Dieppe, France; 4 hours Transmanche
  
• Portsmouth to Le Havre, France; 6 hours LD Lines
  
• Portsmouth to Caen, France; 6 hours Brittany Ferries
  
• Portsmouth to Cherbourg, France; 2:40Brittany Ferries
• Portsmouth to Bilbao, Spain; 36 hours P&O Ferries
  
• Portsmouth to Saint Malo, France; 10:45 hours (9 hours during day) Brittany Ferries
  
• Poole to Cherbourg, France; 5 hours Brittany Ferries
  
• Plymouth to Roscoff, France; 6 hours Brittany Ferries
  
• Plymouth to Santander, Spain 24 hours Brittany Ferries
  
• Poole to Saint Malo, France 4:35 hours Condor Ferries
  
• Weymouth to Saint Malo, France; 5:15 hours Condor Ferries
  

Portsmouth and Southampton act as ports for transport to the Isle of Wight, also Portsmouth , Portsmouth , Poole and Weymouth also have routes to Guernsey and Jersey provided by Condor Ferries

The Irish Ferries Ulysses, the world's largest ferry

• Fishguard to Rosslare; 2 hours Stena Line
  
• Holyhead to Dublin; 2 hours Stena Line and Irish Ferries
  
• Holyhead to Dun Laoghaire; 2 hours Stena Line
  
• Liverpool to Dublin; 6 hours P&O Irish Sea
  
• Fleetwood to Larne; 6 hours Stena Line
  
• Stranraer to Belfast; 2 hours Stena Line
  
• Pembroke to Rosslare; 4 hours Irish Ferries
  
• Swansea to Cork; 10 hours. Fastnet Line Currently suspended, this service will resume in March 2010
  

• Rosyth, Scotland to Zeebrugge, Belgium; 19 hours Norfolk Line
• Newcastle to Amsterdam, The Netherlands; 16 hours DFDS Seaways
• Hull to Rotterdam, The Netherlands; 10 hours P&O Ferries
• Hull to Zeebrugge, Belgium; 8 hours P&O Ferries
• Harwich to Esbjerg, Denmark; 18 hours (3 crossings per week) DFDS Seaways
• Harwich to Hook van Holland, The Netherlands; 7 hours Stena Line
  
• Ramsgate to Ostend, Belgium; 4 hours Transeuropa
  

these routes may be subject to change, it is recommended to contact the ferry operators and book ahead