Magic is a natural force, existing in everything. Modern humans can learn to manipulate energy around them using their own. Fleeing Niras, humans used water and wind to create the first deep-sea ships. Many cultures have a myth of humanity being gifted the power of magic, often sparking the creation of civilization. Storms can be fueled by magic energy, becoming bigger and stronger. While quite rare, there are individuals born without the ability to manipulate the energies.
There are places with concentrated levels of magic energy, where magic is unpredictable and dangerous to cast. Water constantly churns its magical energy, and oceans are the most susceptible to magic-storms. The Intercontinental Current especially is powered by magical energy, and while is vital for the development of modern trade, it's extremely dangerous for the untrained to use.