Choose somewhere very scenic for a first trip - that way if the slow pace is off putting you will have plenty to see. The Llangollen Canal is a great first time trip but avoid school holidays when it gets very busy.
Also, do some research on the route you will take - some of the circular routes you will see advertised can be a bit lengthy for a relaxing holiday.
There was a Narrow Boat in our family from 1972 to 2012 when my parents (at 80) sold their 55' NB - a major lifestyle change for them - their pattern for the previous 20 years had been to set off in April and return home in October. My dad fitted out two boats from scratch - my brother and I helped with the first one. If anyone sees a boat called Basford, it would be nice to know that it is in good hands now.
