Not much of a response, huh? It's probably because we all own our own vessels (or have as an owner/partner some financial institution!) & none of us has any experience with chartering on the bay.
In the heart of Bay sailing in Annapolis is Annapolis Bay Charters--they seem to have a very large selection.
Slightly to the south by auto (a little longer by water) on the West River is Hartge's (pronounced like Archie's but with an "H" at the beginning that IS pronounced) in Galesville. Small fleet & appear to be somewhat older, but this means that the charter rates should also be lower.
On the Eastern Shore & slightly to the north of Annapolis and the Chesapeake Bay Bridge in Rock Hall are 3 separate chartering companies. One of them, Haven, even has an Ericson 34 according to the information.
http://www.rockhallmd.com/rhboat/rhboat.htm
Soory, but I can't vouch for any of them.