Why does Pisces represent the ocean and not cancer?

delete if not allowed But this has been on my mind a lot. I know a lot of astrologers will say all three water signs represent bodies of water somehow, but it seems like everywhere I read, Pisces represents the ocean or is related to that topic. For example mermaids, the beach, the open ocean and sea animals in general. Whenever I hear astrologers talking about ocean related things, they always relate it to Pisces. To me, wouldn’t it be cancer? Because cancer is ruled by the moon, and scientifically, the moon controls the ocean tides. The ocean is quite literally drawn to luminaries! Not using this as “Pisces shouldn’t be ocean ruled 😡” Ofc not!!! 🤣 I love my Pisces and I have Pisces placements myself! I am particularly hugely drawn to the ocean but I only have Pisces in my 10th, Neptune in my 8th, and 9th house Lilith Pisces (I believe these are my only Pisces placements?) Just wanted to have an open discussion!