Do you worry about your yacht...?

Define yacht and define leaving unattended ... How big, what type, how old, docked, mooring...

The concerns for a woodent boat on a mooring which in many parts of the world are called a yacht are not the smae than an 80 footer at a full service marina

That said personnally I m not too concern about water in the bilge but more about loosing electrical and returning to fridges and freezer full of rotting stuff

If, like most people you don't have crew, what to worry about when you are away depends on the size of the boat and where it's located.

Most people use their boats on weekends, holidays, and vacations, and leave them unattended when they return to work during the week.

A well maintained boat under normal weather conditions doesn't need much more than a secure tie up, adequate canvas covers, shut down of non needed systems, power up of needed systems such as shore power, battery charger, automatic bilge pumps, high water alarm, etc. That's more or less the basics for the average weekend boater. Larger boats are more complicated.

Ideally you want to be in a marina with good neighbors who look out for each other (that includes reciprocating) and floating docks are better than fixed docks when a boat is left unattended.

You can hire someone to stop by periodically to check on it and/or install system monitors that you can access electronically ...the sky's the limit in that department.

Even if I'm away from a boat it seems that someone is always paying attention to it for something. Boat washer, repair tech, somebody.

Typically a week doesn't pass without someone onboard.