Young Ray (Kyle Morven Tejpar) seen reading a book "20,000 Leagues Under the Sea" by Jules Verne. The book was influenced by Tennyson's poem the "The Kraken"
When Ray and Nicole climb onto the boat after getting the mask, Nicole's diving balaclava changes from pure black to black with a purple stripe. She also gains and loses repeatedly her diving goggles from the top of her head
When Jim, the skipper, is beheaded and thrown over-board by the wire, we see the actor swimming in the water. Moments later, we see him again moving around in the water as the Kraken's tentacles grab him.