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Marine Life Unit Study: Fun Ocean Activities for Preschool and Early Elementary Kids - Knowledge Crates

Marine Life Unit Study: Fun Ocean Activities for Preschool and Early Elementary Kids

By: Knowledge Crates

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If your kids are fascinated by sea turtles, love pretending to swim like dolphins, or can’t resist collecting shells at the beach, you already know what a natural fit marine life is for early learning.


Our new Explore Marine Life Unit Study blends science, art, storytelling, and sensory play into a hands-on experience your preschool through early elementary kids will love. Whether you use it as a full unit study or just pull in a few ocean-themed ideas to enrich your homeschool week, this one’s packed with fun and discovery!

Why Marine Life Makes a Great Preschool & Early Elementary Theme

It’s no surprise that ocean animals are a favorite topic for young learners. So many are ADORABLE, and they’re all full of mystery, movement, and color—and they naturally spark questions and imaginative play.


With a marine life theme, you can:


  • Dive into science topics like habitats, adaptations, and life cycles

  • Strengthen fine motor and art skills through creative projects

  • Build early literacy with themed read-alouds and storytelling

  • Incorporate sensory play and observation-based learning

  • Spark curiosity with ocean-themed movement, pretend play, and exploration

Best of all, it’s a topic that works beautifully across ages and abilities—perfect for siblings learning together!

Creative Marine Life Projects Your Kids Will Love

This unit is full of hands-on projects designed to help your child explore, create, and connect with the ocean. Below are a few favorite activities we know your kids will be excited to try!

Ocean Wave Art: Paint a Sunset, Sculpt the Sea

This stunning mixed-media project brings together painting and sculpture in a way kids love. First, your child paints a bright ocean sunset background on canvas. Then, using air-dry clay, they sculpt a wave curling across the water—complete with a little whale tail peeking through. It’s creative, calming, and full of texture and color. Plus, it makes a beautiful finished piece your child will be proud to display!

Marine Life Unit Study Wave Painting and Sculpting

Exploring Ocean Animals: Match, Observe, and Imagine

Using realistic ocean animal figures, your child will explore a variety of sea creatures in a playful, interactive way. Kids match each animal to its fact card, then build vocabulary by describing what they see. It’s a great activity for building observation skills and sparking interest in marine biology—no worksheets required!


In another activity, kids will take the exploration outside and use chalk and a measuring tape to mark the true length of these ocean animals ... and compare how many "me's" it would take to size up!

Marine Life Unit Study Animal Facts Cards Matching

How Big Are Ocean Animals?

Get outside and grab your chalk—it’s time to measure! Kids choose an ocean animal, guess how big it might be, and then use a tape measure to draw its real size on the sidewalk. They’ll compare it to their own height and count how many “thems” it would take to match it. It’s a joyful, active way to connect math and science in a way that’s super memorable!

Sea Otter Directed Drawing: Step-by-Step Creativity

Even young artists can follow simple steps to draw an adorable sea otter! This directed drawing (and painting!) activity helps build attention to detail, spatial awareness, and confidence with pencil control—all while focusing on one of the ocean’s cutest animals, the sea otter!

Marine Life Unit Study Otter Directed Drawing

Ice Dye Kit: Make Waves with Color

Jazz up your ocean unit study with a colorful, process-based art project using real ice dye! Kids arrange ice over fabric, sprinkle powdered dye, and watch as the colors melt and blend like rippling ocean waves. The result? TWO beautiful, one-of-a-kind creations you can really use in your home ... pillow covers!

Saltwater Turtle Shell Art

This art-meets-science project is a favorite! Kids begin by painting a sea turtle shell using watercolor swatches on cut-out watercolor paper. Before the paint dries, they sprinkle salt over each color to watch the magic happen. As it dries, the salt absorbs some of the water, leaving behind a beautifully textured, speckled design. Once dry, they rub off the salt and complete their turtle by adding painted flippers, a head, and a tail made from construction paper. It's a great way to blend creativity with observation—and the final turtle is as unique as your child’s imagination.

Marine Life Unit Study Saltwater Sea Turtle Shell Art

Color Diffusing Sea Shapes

In this simple activity, kids paint sea-themed paper shapes with watercolors and watch the colors gently spread and blend across the surface. It's a calm, creative activity that builds fine motor control while introducing basic properties of absorption and diffusion.

Coral Reef Explorers: Look, Learn, and Create

These activities give kids a chance to discover coral reefs through observation and hands-on creation.


First, they’ll dive into coral reef facts and play a fun coral-themed I-Spy game that builds attention to detail and introduces the idea of coral as an underwater habitat. Then, using Model Magic clay, they’ll sculpt their own coral reef by twisting, pinching, and shaping different types of coral—like brain coral, fan coral, and bubbly soft corals. These will get used later in their diorama!

Marine Life Unit Study Coral Reef I Spy

Sea Turtle Life Cycle Diorama

This final project brings together everything your child has learned in a creative, hands-on, and SUPER CUTE way. Using the Knowledge Crates box as the base, kids will create a 3D diorama that illustrates the life cycle of a sea turtle—from eggs in the sand to fully grown turtles swimming in the sea.


They’ll paint the inside of the box to show the water, add layers of real sand and waves to set the scene, and sculpt each stage of the life cycle using clay. From tiny turtle eggs to hatchlings making their way to the water, every detail helps reinforce what they’ve learned about sea turtles and ocean life!


This is one of those projects that feels more like play than learning—but it brings science to life in the best way. It’s hands-on, memorable, and makes a great keepsake to display when your marine life unit is done. 🥰

Marine Life Unit Study Sea Turtle Life Cycle Diorama

Want a Simple Way to Dive In?

You could piece together a DIY marine life unit, but if you’re short on time—or just want everything ready to go—our new Explore Marine Life Unit Study crate makes it easy. It’s designed for preschool through early elementary learners, and every activity is open-and-go with no extra prep required.


Here’s what’s included in the crate:

26 planned activities across science, art, literacy, and sensory play

All materials included (even the glue and clay!)

A full-color activity guide to walk you through it all

I Sea 10! math game from Learning Resources—fun for counting and early addition

An ocean-themed Go Fish! card game for early learners

A shimmering Kinetic Sand mini castle set for sensory exploration

You’ll also receive a curated collection of children’s books that pair perfectly with the activities:


  • The Ocean is Kind of a Big Deal by Nick Seluk – A clever, illustrated book that explains how important the ocean is to our planet and everything on it.

  • Dolphins (National Geographic Kids) – A nonfiction reader packed with photos and facts about one of the ocean’s smartest creatures.

  • National Geographic Kids Ocean Animals Collection – A high-interest chapter book featuring sea otters, manatees, and weird sea creatures.

  • Little Turtle by Gisela Bohórquez – A beautifully illustrated story that follows a baby turtle’s journey from beach to sea.

  • National Geographic Ocean Animals Sticker Activity Book – Full of puzzles, facts, and activities that reinforce learning across the unit.

Everything is packed and labeled—just open the box and dive in!

Homeschooling Older Kids Too?

If you’re teaching older elementary learners as well, this is a great unit to do side by side with our Explore the Ocean Unit Study for elementary kids (best fit grades 2-5). While the younger kids are painting sea otters and exploring ocean animals, your older learners can dive deeper into ocean zones, currents, marine biology, and even a few experiments.


Both crates can be used together for a comprehensive, whole-family approach to learning—everyone learns at their own level, but the theme ties it all together!

explore the ocean unit for homeschool

Go Beyond the Crate: Free Supplemental Library Book List

Books are one of the best ways to bring your marine life unit study to life—and while we've filled this crate with amazing marine life reads, we know that for lots of homeschoolers, you can never have too many books to go with your theme!


That's why we've created a free printable Ocean Library Book List with fiction and nonfiction titles for all reading levels. From board books to early chapter books, it’s full of titles your whole family can love!


Print it, bring it to the library, and fill your homeschool days with colorful, engaging stories about the sea.

Marine Life Unit Study Ocean Book List

Ready to Make a Splash?

From adorable art and stories to sensory play, games, and hands-on math, this unit is packed with joyful, ocean-themed learning your kids won’t forget. Whether you’re looking to create a full marine life unit study or just want to explore the sea a little at a time, we hope these ideas help you dive in with confidence!


And if you’re ready for everything to be organized, prepped, and delivered to your door—books, materials, pacing and all—we’d love for you to check out the crate. However you choose to explore marine life, we’re cheering you on!


Happy homeschooling! 🌊🐚🐠

author

Author: Elizabeth, Team Knowledge Crates

Elizabeth is a former public school teacher turned homeschool mom. She's been homeschooling for six years with her kiddos who are currently in kindergarten and third grade. At Knowledge Crates, Elizabeth develops the elementary unit studies and test-runs activities with her kids.

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Frequently Asked Questions

What is Knowledge Crates?

Knowledge Crates are thoughtfully curated and secular educational activity boxes designed to make learning fun, hands-on, and stress-free for families.


Each crate is packed with activities, books, and all the materials needed to spark curiosity and creativity in children.


Whether you're a homeschooling parent or simply looking for screen-free ways to keep your kids engaged, Knowledge Crates provide a convenient and enriching solution that fosters exploration and discovery.

Who are Knowledge Crates designed for?

Knowledge Crates are designed for families with children ranging from preschool to high school.


Unit Crates: The preschool units are ideal for children from preschool through grade 1. While some of the skills included may already be mastered by older kids in this range, this gives children a sense of accomplishment as they confidently complete activities on their own! The elementary units are tailored for children in grades 2–5, providing more challenging and engaging activities to keep them excited about learning.


Mini Crates: These versatile crates are designed for children ranging from preschool all the way through high school. Each mini crate includes a detailed list of what’s inside, along with photos of the materials, so parents can easily choose the best fit for their child’s interests and age group.


Sensory Play: Loved by kids of all ages, our sensory play options provide hours of engaging, hands-on exploration that fosters creativity and fine motor development. Whether your child is a toddler or older, sensory play is a hit in every home!

Can Knowledge Crates be used as part of a homeschool curriculum?

Absolutely! Knowledge Crates are a fantastic addition to any homeschool routine. Whether you’re looking to supplement your core curriculum or need ready-made activities to engage your kids, our crates provide all the materials and guidance you need.


Each unit study crate is carefully designed to explore a specific theme in depth, from the wonders of the ocean to desert habitats and beyond. The step-by-step guides and hands-on projects make it easy to incorporate crate activities into your lesson plans, saving you time and adding variety to your homeschool day.

Will Knowledge Crates really work in my homeschool?

Every family is different, and that’s why we design Knowledge Crates to be flexible. Whether you’re homeschooling full-time, looking for weekend activities, or need an engaging way to keep your kids learning during breaks, our crates adapt to your needs. They’re perfect for preschoolers exploring sensory play or older elementary kids diving into creative and STEM-focused projects.


And if you're worried about the value, consider this: everything you need is included. No hidden costs, no extra materials to buy —just open the box and start creating moments of learning and discovery. The materials are even reusable, so many of the activities can be enjoyed again and again!

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