Tidal forces from the moon and sun cause the earth's oceans to increase and decrease in height throughout the day. This change in vertical height causes a change in horizontal speed of ocean water. Each day has two high tides and two low tides, whose timing changes with the phases of the moon. I like to consult a tide chart whenever I go kayaking around Jetty Island in Everett. The tide chart below shows the average ocean water height in Everett on June 24, 2021. Jun 23 2:52 PDT 14 ft 12 ft 10 ft Tidal Heights at Everett, Washington Thursday, June 24 2021 8 ft- 6 ft- 4 ft- 2 ft 0 ft- -2 ft. Jun 24 3:52 PDT Moonset 4:47 PDT 3 4 5 6 23 Other Tide Stations Previous Everett, Washington Jun 24 11:06 PDT 4758.8'N12213.4'W Map Monthly Table Jun 24 18:47 PDT Jun 24 23:51 PDT Full Moon Moonrise 21:47 PDT 11:40 PDT 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 0 Other Current Stations Next 1. What times were the high tides that day? What times were the low tides? 2. Because this is a graph of position versus time we can infer velocity information from it to some extent. Recall that velocity is the slope at some instant in a position versus time graph. When paddling in a channel, like the one between Jetty Island and the Everett Marina, experienced kayakers avoid trying to paddle against strong tidal currents because the horizontal speed of the water flowing in or out with the tide may be faster than a person can paddle. What times of day on June 24, 2021 were the best for paddling? 3. Crabbing on the other hand, is best when the currents are fast. Since crabs are slow underwater walkers, a fast current will help more crabs to walk past your crab pot and possibly be caught. What times of day on June 24, 2021 were the best for crabbing?