Heals a friendly target for X and another X over 18 sec. Your Chain Heal spells are 25% more effective when their primary target is affected by your Riptide.
Riptide is a shaman ability learned at level 10 for those with the restoration specialization. It is an instant cast healing spell with a heal over time effect. If the shaman casts [Chain Heal] on the target while the Riptide buff is still up, it gives the chain heal a 25% increase in healing.
Similar to a druid's Regrowth spell, Riptide is both a direct healing spell and a heal over time spell. The direct healing part of the spell can crit, but this will not increase the healing done by the HoT component.
Being instant, the spell cannot be interrupted, which makes it a very powerful ability in PvP