Here are the Sailing Directions for the Shannon Estuary (completed before 1848) and for Lough Erne (1835-6), Lough Ree (1837) and Lough Derg (1838-9). They were compiled by Commander James Wolfe RN, who was one of those who drew up the relevant Admiralty Charts. Like the Charts, these Directions have not been updated, so boaters should not rely on them for navigation.
The Google Books Team have kindly permitted me to extract these from a larger document, which was one of those they had scanned and placed online, and to make them available (free, of course) to visitors to this site. Note that I have omitted part of the description of the smaller Lough Derg, which is not part of the connected waterways system.