ATSC 113 Final Exam Study Guide Swell direction is forecast in: Degrees. When sailing, it's best to head into swell at a: Angle. A good determinant of
... [Show More] swell is: Wave height and wave period. "Swell of 6ft and 15 seconds" means: Wave height of 6ft, wave period of 15 seconds. Two types of wind to consider when dealing with swell are: Onshore and offshore wind. Onshore winds blow in what direction and have what effect? Onshore winds blow from the ocean to shore, and can reduce wave steepness. Offshore winds blow in what direction and have what effect? Offshore winds blow from the shore to ocean, and slow the speed of waves. How can tide affect how swell breaks on the shore? Tide changes the place where the water meets land, changing the contours of the shallow water where swell breaks into breakers. Describe swell refraction. Area of swell hits an area of shallower water (reef, rock, etc) and experiences drag. Rest of swell curves around this area experiencing drag. Swell with ________ wave periods will refract more than swell with __________ wave period. Longer, shorter. Swell decay: How quickly waves lose energy as they travel from their initial source. What factors are important when deciding how swell will break on a beach? Local conditions, swell height/period, swell direction. What factor isn't important when deciding how swell will break on a beach? Great circle routes. What factor doesn't influence how swell will decay? Surface water. True or false: Offshore winds blow from the ocean onto the shore, creating chop on the incoming swell. False. Tide: Movement of Earth's oceans up and down due to gravitational pull of moon/sun. Spring tide: Sun and moon line up, creating higher and lower tides than usual. Neap tide: Weaker tides when sun and moon are at right angles to each other. Tide table: Chart displaying tidal patterns. How many tide cycles will you encounter per day? Two (So two high tides and two low tides.) Tidal range: Difference between highest tide and lowest tide. Flood current: Current created by incoming tide. Ebb current: Current created by outgoing tide. Tidal currents are stronger: Mid channel, or in deeper water. Seas are calmer when tidal current and wind: Travel together. Tidal rapids: When tidal currents forced through narrow corridor. Environment Canada broadcasts warnings and forecasts for the Pacific. This is called: The Continuous Marine Broadcast (CMB). CMB can be accessed by what type of radio? VHF radio. [Show Less]