Hi Ronin and welcome to the forum.
Impossible to say how much the yearly maintenance will be. Like asking how much monthly maintenance will be on a car. First it will depend on a several things:
How old is it and what kind of condition is it in?
Then, are you counting just regular stuff like change the
oil,
paint the bottom and such, or are you including the big things that may only come up after many years or even almost never. Again, like owning a car. Doesn't cost much for maintenance month to month until the
transmission goes and you have to shell out $3,000. Or a house; doesn't cost much every month until you have to put on a new roof.
Boat maintenance monthly, if the boat is in reasonable shape isn't much but every 10-20 years you have to replace the standing
rigging (the wires that hold up the mast). 36' boat would be about $3000 installed. Every 5-20 years (depends on how much sailing you do) you will have to replace the
sails. 36' boat figure $2-$3000 each (main and jib).
Hope you won't have to replace the
engine but just like a car every once in a while you are unlucky. New
diesel for a 36' boat installed could run $10,000, plus
transmission.
Docking fees vary a lot depending on the area and are charged by the foot. So bigger boats cost more. Don't know the
west coast but NY and north figure $1000/month for all season or $100/night for a visitor. Pay a third of that in small towns in north FL or VA or NC or even TX.
Do a little
research on this forum for previous discussions on this topic. It is one of the most frequently asked (and answered) so lots and lots of information already here.