When we are in open sea, we have time to carefully plot our position, however when we are near the shore things and situation can change rapidly. There is less emphasis on using techniques like plotting fixes or running up course to steer plots, sometimes its a complete waste of time as the scale of things change as we move inshore and what we become more concerned about is being able to avoid dangers and obstacles.
We want to avoid dangerous stuff below water level like rocks, wrecks and other submerged obstructions. We need an appreciation and knowledge of where the shoals and shallows are and what tidal height is required to pass safely over the top of them.
A good a watch is always required on a boat at see but becomes increasingly important as we move into area with a higher concentration of boat traffic.
As we approach shore tidal streams can become more flukey and eddies develop, we need to be aware how the vessel is responding to tidal currents as it may be moved into dangerous positions or nearer a hazard by the tidal currents.
Its a good policy to give everything a wide berth and overcompensate your manoeuvres around obstacles but equally important for other water users to understand your intentions so that you do not impede each other.