may stay dry even if you swim for a bit. But I would prefer to rely on my roll.
If you use a drytop, I recommend that your skirt tunnel be a bit looser, so you're not fighting it with torso rotation. *Also* if you find you have to roll down the top of the skirt to fit the drytop, trim off the top of the skirt accordingly.
Kayak Motor Kit
Canoe / Kayak Anchors