As a first time water crosser remember only you know the aircraft is over water the aircraft does not and its strange how a normally smooth running engine suddenly takes on a different tone and freaks you out! I am sure that over water you become more aware of the engine sounds and imagine all manner of ills.
Check the engine gauges on a regular basis, try to change tanks if possible over land.
Personally, I get to my planned crossing altitude and power setting then change tanks, about 5 min before coasting out, and then don't touch anything apart from regular application of carb heat. If you fly on one tank for as long as your crossing before starting the crossing, then you'll be balanced at the end. I'm not sure yet whether I would rather ditch, or land in a ditch!
Thanks Malcom.
It's been awhile since I updated it, so probably due for a few updates such as those you suggested. I'll put them in asap.
dp
One further thing, when we bought fuel in Waterford to depart to Inishmore, we were charged VAT at 23%. Departing from Waterford to Popham we weren't. That brought the price down to £1.76/litre. The best way then seems to be fuel up before you go, or land somewhere like Haverfordwest to refuel, then fill up on your way home.