Using the harvesting blade on kelp doesn't work the way you'd expect considering how it works with crops. It doesn't break kelp until it's a block higher than the blade, after which it breaks both and only collects the bottom one (in the chest attached to the mechanism) leaving the upper piece of kelp to float to the top of the water. Is this intended behavior?

At first I thought the not-harvesting-until-2-blocks-tall was to make up for the fact that it cant replant it, but then it breaks both blocks anyways. Shouldn't the behavior be that when it collides with kelp on the same Y level, it breaks (and collects it in attached chest) so no kelp goes floating off? Then you could just plant the kelp one level below the mechanism and have it grow and get harvested automatically without needing some kind of collection system at the top. Or at least collect kelp attached to the piece it is cutting.

You can use saws to harvest kelp effectively in 0.2.3. I'll look into giving the harvester similar abilities