Answer: Tides cause water levels to rise and fall.
Step-by-step explanation:
When boating in coastal waters one must have the effect of tides in mind. Usually, changing tides are predictable, as variations commonly appear twice every day at around six-hour intervals. The rise and fall of tides can change water levels by a lot, and strong currents may also develop. Tidal currents can get so strong that a boat may not be able to make headway against it.