Best way to create foam around monster tentacles on water

I would like to make a monster with many tentacles and those tentacles had around a foam on water, no matter how deep is the water, as it could be in middle of the ocean, and one tentacle could be with S shape, part above the water, part at water level making foam and part under the water. The only way i see to do it is placing many objects with a particle system each that when tentacle collides the particle emits, but maybe there is a better way to do this.

Also would like to have the tentacle drop some water when goes down the water and goes up, i guess particles using collision will go up with the tentacle and drop to the sides?