Maelstrom

Acquisition
Skill Quests: Skill Trainers: Signet of Capture:
 * None
 * Avena (Maguuma Stade)
 * Tengsao (The Amnoon Oasis)
 * Dakk (Ember Light Camp)
 * Wydd Kindlerun (The Wilds (Mission))
 * Fryn Rageflame (The Falls)
 * ... more to be added ...

Usage Notes

 * Because of the high cost and long activation time, this spell is not for interrupting a specific spell, but rather for shutting down spell casting in an area.
 * Glyph of Energy complements this spell well, because Maelstrom costs so much energy and causes exhaustion too.
 * Maelstrom is easily avoided by leaving the area of effect. That makes this skill more useful in PvE than in PvP. In PvE it used to completely shutdown a group of enemy casters singlehandedly (computer controlled enemies used to not move out of the area although the November 11, 2005 update altered AI so they run out of AOE). In PvP, this spell can cause havoc among a group of spell-casters standing next to each other as well as spell-casters who like to tank the opposing team's warriors (like a protection/smiting monk). Maelstrom will disrupt a few of their spells and as they panic and try to run, the warriors will inflict a lot more damage.
 * One of the most useful spells without investing in their linked attribute. The damage of the spell is not that high, the appeal is the effect of 10 seconds of interrupts every second. This effect is achieved even with 0 Water Magic.
 * Can be very powerful in combination with slowing skills and/or knock-down skills, making it hard for people to get out of the AOE (Deep Freeze, Ice Spikes, Frozen Burst, Water Trident)