Seaside Shore has some nice, detailed fish images, along with seaweed & rope. This is my stamp for the August calendar page.
I’ve used a Masking Technique to stamp the bottom fish in Calypso Coral, then cover him with a post-it note that I’ve cut out in that shape. Then I was able to stamp seaweed right over it without messing up the fish. Other colors: Dapper Denim, Daffodil Delight, Wild Wasabi, Soft Sky.