Been told by Solent that the fuel guage on the Opti is very unreliable becasue of thin profile of tank. In other words, the only way to find out how much fuel you have is to keep track of how much you have put in (from credit card slips in the wallet, I asume

), and subtract the amount you have used (from the Opti guage I assume).
This seems clumsy at best. Anyone got a better idea? How do people handle this problem, or is it specific to Solents?
Anyone know where I can get cheap big jerry cans - preferably plastic. Fancy two 22litre jobbos as a reserve.
Thanks
Bruce