(N/A) Two different ways of harnessing energy from the ocean are:
$1$. Tidal Energy: This is generated by utilizing the rise and fall of ocean water levels due to the gravitational pull of the moon and the sun. Dams are constructed across narrow openings of the sea to trap water during high tide and release it during low tide to rotate turbines.
$2$. Wave Energy: This is harnessed by capturing the kinetic energy of ocean waves. Various devices are used to convert the oscillating motion of waves into mechanical energy, which then drives a generator to produce electricity.
$3$. Ocean Thermal Energy Conversion $(OTEC)$: This method utilizes the temperature difference between the warm surface water of the ocean and the colder deep water to run a heat engine and generate electricity.