In 1837 Commander James Wolfe RN and Lieutenant R B Beechey RN surveyed Lough Ree; they produced an Admiralty Chart and Commander Wolfe wrote sailing directions (available here).
But while surveying they also made drawings — Views of Lough Ree — showing what a ship’s master might see from certain locations on the lake. Those drawings were held in the United Kingdom Hydrographic Office until 2003, when they were transferred (with other historic documents) to the National Archive of England and Wales.
I have paid the appropriate fee permitting “reproduction of images of documents from The National Archives on an open non-commercial website” and I show some of the drawings here. I am required to show them at low resolution; you’ll get a somewhat larger version if you click on each in turn, but it will still be well below full size.
The equivalent drawings of Lough Derg are here.