How much is a sheduled river boat service with a 7 days travel card?

I am going to visit London with my family.
I read travelcards are valid for sheduled riverboat service, and you pay a reduced fare. Can you also add details about what a sheduled river boat is? I mean where you start from and whare you arrive.
Thank you for your help

Check out the Transport for London (TfL) Website ! It has all the information that you require !

as far as i remember the all day travel cards includes the boats

on this page there are links to the riverboat map and timetables
http://www.tfl.gov.uk/modalpages/2648.aspx

Riverboards are not free with a Travelcard but it says ...
"Many operators offer 33 per cent off normal advertised adult and child fares on production of a valid Travelcard or Oyster Card, loaded with a valid Travelcard, when purchasing a ticket. Some restrictions apply. Oyster cards with pre-pay are not accepted."