Attended a very good talk at the PEYC as part of their Winter Talks series on Tides and Currents at Port Edgar, given by Jim Scott.

One tip was that because of the various historical naval uses of the area there has been some very detailed surveying of the currents in the Forth and this can be purchased in the form of the Admiralty Tidal Stream Atlas NP220 - Rosyth Harbour and Approaches.