The best and easiest maintenance for your boat is to simply get out on your boat an use it. Problems often start after long periods where the boat has not been used!
Obviously there will be times when you are unable to use your boat. Winter is probably the time where you will get the least use out of your boat. But in summer when the weather is good, you should get out on your boat as much as possible.
Using your boat frequently will prevent seals from drying out and keep all parts of your boat nice and lubricated. Your fuel tanks will not fill up with condensation as you will regularly be using old fuel and replacing it with new fuel. Problems occur most of the time when boats are neglected for long periods of time.
So what do you do if you must leave your boat for a long period of time? Firstly, consider turning the boats engine over at least once a month. Make sure the engine runs for about 10 minutes minimum. If you have an outboard be careful to ensure a water supply is pumped into the motor to prevent damage. You should also always watch this water supply as hoses can become kinked and kids can turn them off which can result in extensive damage to your motor in seconds.
Try running all other devices in your boat to keep them in a good state. This includes all elecrtical devices, pulleys, steering, winches and cables. A quick flick of a switch once a month may save costly repairs down the track.
If you have an outboard motor and plan to not use it for an extended period of time, be sure the motor is trimmed down to ensure parts of the motor stay lubricated. If the boat is kept outdoors be sure to purchase a good quality boat cover to keep it out of the elements.
Basic maintenance indeed, but these small tips could save you big money repairs.