1.) Never drive under the influence of alcohol. Many accidents of this type occur after leaving the local sea-side snuggery for home port. Have a designated drive, just like with your automobile.
2.) Do not go any faster at night than you can see ahead what is actually on the water. This means drive slowly at night.
3.) Everything appears differently at night, so don't assume that you know where you are, even if it is in your home port. Stop, get your bearings, make sure you are in the right location, and then proceed carefully.
4.) In the daytime, approach all harbors, bays, inlets, beaches, and moorage areas with caution. Just because you don't see a breakwater doesn't mean there isn't one there, either man-made or natural. Check your charts and chartplotter; look for channel markers; and, if you are unsure, get on the VHF and ask for advice from the locals.