Hi KB
A few boats do have water gauges and toilet holding tank gauges but are probably the exception rather than the rule. They are handy though! Avoids the guesswork. Swancraft have been trialling a very nifty water gauge which works on tank pressure rather than having a sensor in the tank itself, so they can be fitted retrospectively. If you are hiring on the Southern Broads, Swancraft are well worth considering. Family run yard, very personal attention, and above all well maintained! I have no connection BTW, just a very satisfied customer.
If I can jump in for Jonzo – Broadlander is the new boat from Richardsons – beautiful boat and another one you might well consider. Richardsons have an excellent well deserved reputation. There is a thread about it being built.