During our hike we come to a beach that is 4 m above sea level. The first high tide occurs at 2:00 am at 7.4 meters. The second low tide occurs at 1:45 pm at 1.4 m below sea level.

At what times can we cross the beach without getting wet? If the sun rises at 7 am and sets at 8 pm. When is the best time to cross the beach if it takes 2 hours to cross?