Some items are provided but we would recommend:
Essentials
Bedding including pillows, linen and duvets or sleeping bags.
Suitable clothes for walking and working locks.
Provisions especially for a meal the first night.
Cash as not all pubs and canal shops take card payments.
Sunglasses, sunhat and sun cream.
Mobile phone charger
For wet and / chilly days: warm/waterproof coat, gloves and a warm hat.
For pets: bed, feeding bowls, lead, scoop and poo bags and towels for after their swim (planned or otherwise!).
Other useful items:
Camera, binoculars, radio, CD player and games.
Picnic/folding chairs
Coolbox
Bicycles
Fishing rod