I've seen hundreds of first-timers make the same mistakes on the water. Here's what trips people up the most:

1. Not checking the weather before departure.

A calm morning can turn into whitecaps in 30 minutes. Always check the marine forecast, not just your weather app. Look for wind speed, wave height, and storm warnings.

2. Forgetting the pre-departure checklist.

Fuel, drain plug, life jackets, fire extinguisher, navigation lights. Miss one and you're either sinking, stranded, or getting a fine. It takes 3 minutes — do it every time.

3. Coming into the dock too fast.

There are no brakes on a boat. You need to learn to use reverse thrust and approach at idle speed. The saying is: "never approach a dock faster than you're willing to hit it."

4. Not understanding right-of-way rules.

It's not like driving a car. Sailboats generally have right of way over powerboats. Boats on your starboard side have priority. Learn the basics before you leave the marina.

5. Ignoring the capacity plate.

That number on the transom isn't a suggestion. Overloading changes how the boat handles and can make it capsize in conditions that would otherwise be fine.

If you're renting a boat on vacation and want to feel confident instead of anxious, I put together a complete workbook covering all of this and more — safety, regulations, maneuvers, and checklists. Built specifically for people with zero experience.