What You'll Get
Choose Between Two Options
- $59 for a 60-minute introductory kiteboarding class for one ($125 value)
- $115 for a 60-minute introductory kiteboarding class for two ($250 value)
Tides: A Common Sight on Opposite Ends of the Earth
Throughout the day, the sight of a shoreline can change drastically up to four times. Check out Groupon’s guide to understand the mysterious forces behind the tides.
Part of Mother Nature’s daily chores, tides are easy to take for granted, but their existence is a reminder of how the earth’s rotation stays a steady course. For the most part, tides are caused by variations in the gravitational pull from the moon (and the sun, to a much lesser extent). With some exceptions, most regions of the earth experience two high and two low tides daily, even though the moon’s revolution takes roughly an entire day. Here’s where the variation comes in. Where the moon is closest to the earth, its gravitational field is also greatest, and the ocean bulges toward it to create a high tide. At the same time, the earth’s opposite side faces the least gravity, which means the water bulges away from the moon—also causing a high tide, from that side’s point of view. At the two points between each high tide, the ocean squeezes slightly inward, and the tides recede.
If the earth were a perfect sphere without any continents, scientists say, all areas on the planet would experience two equal high and low tides each day, as their travel from east to west wouldn’t be interrupted by land. Instead, variations once again affect the size and frequency of tides, particularly in the different shapes of shorelines. For example, the Bay of Fundy in Nova Scotia experiences some of the highest tidal differences in the world—often up to 16 meters—because of its V shape, which causes the water to build up as it funnels inward toward the point. Local wind and weather patterns play a part as well; high winds can push water toward the shore and cancel out a low tide, and high-pressure systems can lower sea levels, drastically lowering the tides and spoiling the mermen’s plans for invasion.
The Fine Print
Promotional value expires May 29, 2016. Amount paid never expires. Must sign waiver. Registration required. Limit 1 per person, may buy 1 additional as gift. Limit 1 per visit. Valid only for option purchased. All goods or services must be used by the same person. Merchant is solely responsible to purchasers for the care and quality of the advertised goods and services.