There are many Houseboats to choose from & that many gaps in the total package, so be prepared . The experience on being on a house boat for leisurely sail through Kerala Back waters are no doubt very relaxing, but if not prepared for surprises like insects or flies in the night, contaminated supply water in toilets, one can be disappointed.
We had similar experience in one House Boat " Shiva Ganga" arranged by Kerala Travel Club.We were given one route by travel agent "KTC", while on board , we were told a different story. But due to our persuasion the boat guys agreed with the original plan.
It is safe, but better to be accompanied with two or more families.One should insist on a Houseboat having dining area covered ( enclosed area )so that there is no black out temporarily in the night.One should address spicy foods that are cooked by the multi tasked houseboats boys intelligently or else suffer.