There are some things that need to be done in any home. But it is worth considering them here.
The basic example is, having a spare.
If you use something regularly, like hand-soap in the bathroom or jam, then keep a spare in a handy place.
When the jam runs out, replace it with the spare and write jam on the shopping list under the magnet on the fridge door.
This applies to fan belts in cars as well as boats, certainly Gas bottles if you use gas on board.
If you have a fuel tank in your car or boat, carry a small can of fuel just in case. On a Static houseboat the spares will be identical to those in a home. But one ESSENTIAL for a static houseboat is a long leasehold OR Freehold Mooring
A residential cruiser has two extra areas of consideration. All the spares needed for the engine, generator and cruising equipment. Depending on the length of cruise, more household spares maybe needed if planning to be out in the country away from boat- yards, roads and shops.