Passing and Being Passed
Passing moored boats is easy. JUST SLOW DOWN.
Yes it is true that it is the responsibility of the moored boat to tie up correctly and it is true that many don't. But, regardless of that, if the passing boat slows down to engine tick over then it almost won't matter how well the boat is secured.
Keep well clear of the other boat. There might be reasons why you can't give a wide berth such as shallow areas or overhanging trees or perhaps because there is another boat coming in the opposite direction. But the more room you can give then the better. Try to avoid that invisible magnet that seems to draw boats together.
Passing moving boats can be just as easy with a little consideration.
If you are the boat in front then recognise that some people want to make more progress than you and allow them to pass as soon as you can. Pick a clear and wide bit of the waterway and signal the boat by waving your arm. Move over to one side, (but not too close to the bank) and slow right down to begin with even using reverse gear if you have to. When the boat gets close, increase engine speed to tickover to keep enough power for steerage. Be aware that the overtaking boat will draw the bow of your boat towards their stern as they almost complete the overtake.
If you are the boat that wants to pass then be patient and don't attempt to pass until the leading boat has signalled. Then pass as slowly as possible but as quickly as necessary.
Overtaking should only normally be done when both parties agree!
There are horn signals to request overtaking but these get quite complex and most people don't know what they are so your signals might be wasted.
Slowing to engine tick over is the way to pass moored boats but if you don't slow the engine down until you are on top of the other boat, then you will still be travelling too fast. As a general rule, (and there are many factors involved), if you are cruising at a steady walking pace, then it will take at least two to three boat lengths to slow down sufficiently.
Slowing the boat down early will also give you the opportunity to use engine power/prop speed to have greater manoeuvrability if a gust of wind should make passing difficult. If you are still slowing down as you are passing the boat then your rudder control will be much reduced.
If you come across a boat that has come adrift from its moorings then consider stopping and having a crew member secure the drifting boat. There are legal implications of moving someone else's boat so take care. See the LIABILITY section.
Avoid getting annoyed if a boat is passing your moored boat at speed when conditions are windy. It might be the only way they can get past with control. If they are Considerate Boaters then they will have slowed the boat down well before trying to pass you and it will only be the engine speed that is high in order to maintain rudder control.
Don't just listen to engine speed to judge someone's boat speed. There are many boats on the waterways now that have electric or hydraulic drives and engine speed may not be an indication of prop or boat speed.