The coastal trails in my area all come with warnings about reading and understanding the tide tables, and they post current tide predictions at every trailhead. When you're hiking, this is important as there's areas that are cut-off by high tide and can leave you stranded for hours, or at least very wet.

Last year, when we were camping on a beach, some teenagers made a noisy entrance onto the beach after hiking with 60 pounds of gear each (20 pounds was probably the beer). They looked around, and saw everybody's tents huddled in a small area up near the trees, then looked the other direction and chose a nice, flat, sandy spot near a waterfall. They excitedly set up their tent and had a good time, while the rest of us debated whether to enjoy the quiet afforded by their distance from us, or to advise them of their poor choice and invite them to share our small spot. Eventually a few of us did ask them if they were aware of the tides, and they said they were and camp here all the time. Okey dokey.

Around 3:00 am, right around the full-moon high tide, we were all woken up by panicked shouting. Luckily, the noise of the crashing waves mere feet from our tents drowned out most of the sound, so we were able to go back to sleep easily. When we woke up in the morning, the teens were fast asleep in the trees, wet gear draped from various branches.

Lessons:
1) read the tide table
2) understand the tide table
3) respect advice from more seasoned hikers
4) if the "perfect spot" isn't taken, stop to wonder why
5) nature is a mother