"Poseidon is the Olympian god of the sea, earthquakes, floods, drought, and horses."
Water from rivers, lakes, rain, etc.
White wine poured into water
Homemade fish stew, clam chowder, etc.
Horse shaped crackers or cookies
Ocean and rain scented incense
Horse, ship, or dolphin statues
Impossible bottles (ship-in-a-bottle)
Blue, green, and silver candles
Ocean and sea scented candles
Wreaths made from wild celery
Starfish or starfish decorations
Gems such as pearls, sea glass, blue sapphires, aquamarine
Toys or art of dolphins, fish, and/or horses
Art, toys, or photos of tridents
Photos or art of the ocean
Naturally shed shark teeth
Ocean scented essential oils or perfumes
Art of hippocamp (half-horse, half-fish creature)
Art or figurines of ships and sailors
Donate to ocean conservation in His name
Donate to coral reef restoration programs in His name
Donate to natural disaster relief programs in His name
Help clean up oceans, beaches, lakes, rivers, riverbanks, etc. (Be careful when cleaning up litter)
Visit bodies of water and enjoy the beauty they offer
If you can't visit any then watch videos of the ocean or listen to the sound of waves
Wear seashell jewelry or fish-shaped jewelry
Meditate at bodies of water, in the shower, or while listening to the sound of waves
Take baths and surround yourself with images of the ocean
Ask Him to aid you in bath and weather spells
Get a pet fish if you are able to take care of it
Learn about marine biology
Learn about natural disasters and what to do during one
Wear blues and greens or clothes with horses or dolphins on them
Decorate your room with a nautical theme
Research and work with mermaids, sirens, and the fae
Pray to Him for rain or for rain to stop, for earthquakes or floods to end, for protection, for safe travels across the sea, for healthy horses
https://vocal.media/futurism/ways-of-worship-poseidon
https://www.theoi.com/Olympios/Poseidon.html
https://hellenicfaith.com/poseidon/
http://zer0dmx.tripod.com/gods/poseidon.html