conditioner

Hi Boaters, I have a 60 Sundancer and need some help with two issues. 1) Any recommendations on how to extend the time it takes before the fresh water “goes off”. I usually try to get away for three day weekends only to find the 2 hundred gallon water tank needs to be drained and refilled...

Can anyone provide information on aftermarket air conditioners for a 2008 Sea Ray 260 Sundancer like make and models, where to install on boat, parts needed but were not aware of at time of purchase, or any other helpful hints. Any information would be appreciated. Thanks!