Seals 1: The sense of motion is a good starting point, but the animal looks more like a fish than a seal. I'd rely heavily on reference photos. Maintain a consistent line style--some of the linework towards the bottom looks very shaky. Build your forms from shapes rather than drawn lines.
Seals 2: These seals look better, but there is something almost psychedelic about the whole logo that completely does not work. Simplify, simplify, simplify.
Kraken 1: This one has the most potential of the bunch. Ditch the textures, the gradient, and maybe even the skyline. Do something to the kraken so it looks like something more than just an octopus. The helm is missing a handle in the upper right.
Kraken 2. Overly detailed, especially the tentacles, which also seem to be coming from multiple animals. Gradients are not your friend. The S doesn't look like it relates to the rest of the logo--in color, style, and linework.