Hi reference using the water from the lake, I have not noticed any adverse issues and will continue to monitor the situation. The water is taken from about an inch below the surface of the lake and goes through a sintered bronze filter as used in model airplanes. This type of fuel filter was suggested to me by a fellow Mayhemer (thank you), and so far it is an improvement on the filters I had used in another boat.
The issue I had with the other boats filters was that they blocked, they were installed in a system with onboard water tanks and the water used was distilled water. I believe the issue was because of many different metals in contact with the water, brass, copper, aluminium, steel mesh filter, etc etc. The Filters look identical to the ones Raphael is using. The problem with them was that the aluminium corroded and it was difficult to undo them. I tried greasing the threads, but it didn't really improve things. The main issue was the mesh became blocked, please see photos, this combined with them corroding meant I looked for alternatives.
The filter I now use has remained easy to undo and the sintered bronze filter pops out and can be rinsed under a tap before being replaced, its working much better.
Re the fenders, thank you, guilty as charged, I shall not repeat that mistake - every day is a school day.