[Free Download] Underwater Background Illustrations (Portrait) — Commercial Use Allowed (Free) for copainter Users

We are offering free underwater background illustrations in a portrait 9:16 format. These vertical assets are ideal for smartphone-oriented projects, and lighting-off (dark) variations are also included, making them especially versatile.

They can be used for webtoons, games, manga, and other projects including advertisements.
Commercial use is allowed, free of charge, and tracing and additional edits are permitted.

Please save and use the images directly from this page.
For licensing details, please check the end of this text.

File Details

• Format: PNG (non-transparent)
• Aspect Ratio: Portrait (optimized for smartphone viewing)
• Resolution: 768 px (W) × 1344 px (H)
• Download: Save each image individually below
  (Note: No bulk ZIP download is provided.)

Underwater Manga / Anime Background Illustrations (Downloadable)

Cove of Sunken Ruins and a Shipwreck | Blue Fantasy

Light streaming through the clear water illuminates a sunken ship and coral reef, creating a quiet and mysterious underwater scene.

Shipwreck on the Seafloor Bathed in Sunset Light | Orange-Toned Fantasy Sea

Warm sunset light filters down from the surface, softly wrapping the shipwreck and coral in a gentle underwater glow.

Deep-Sea Ruins Under Moonlight | Night Ocean

A fantastical night-time underwater background wrapped in deep blues, where ruins and sea life rest quietly.

Sunlit Coral Reef Path | Tropical Aqua

A bright and refreshing seafloor scene filled with colorful fish and jellyfish, bursting with a sense of life.

Coral Garden in Afternoon Light | Sunlight Blue

A calm underwater scene where golden light shines through and sea turtles and fish glide gracefully.

Pre-Dawn Seafloor Corridor | Deep Blue Moon

A coral-lined path bathed in pale, moonlike light, with softly glowing jellyfish drifting in the darkness.

Crystal-Clear Seafloor with Swimming Manta Rays | Aquarium Light

A pure and transparent shallow-water scene where sunlight filters in and jellyfish and fish float peacefully.

Sunset Coral Reef and Dancing Jellyfish | Pink Ocean

Warm evening light pours into the sea, creating a dreamy scene with drifting jellyfish and vibrant coral.

Silent Deep Sea with Glowing Jellyfish | Night Blue Abyss

A mysterious and tranquil deep-sea space where faintly glowing jellyfish drift through dark blue waters.

Quiet Seafloor Path with Beams of Light | Sea Blue Horizon

A soothing underwater scene with gentle sunlight illuminating the seafloor as manta rays swim calmly.

Sunset Seafloor Canyon and Manta Rays | Sunset Ocean

Dramatic underwater scenery where sunset rays stream through rocky terrain as manta rays glide by.

Moonlit Seafloor Canyon and Manta Rays | Deep Night Blue

A calm, deep-blue underwater background with shimmering light, ideal for exploration or infiltration scenes.

Sunlit Coral Reef and Sea Turtle | Clear Blue Shallows

A bright underwater scene where surface light spreads across the sea as a sea turtle swims peacefully.

Sunset-Colored Coral Reef and Sea Turtle | Pink Sunset

Warm-toned light softly envelops the underwater world, creating a soothing and nostalgic atmosphere.

Coral Reef at Midnight with Sea Turtle | Night Dive Scene

A dark underwater scene with faint light, expressing both silence and tension.

Sunlit Shipwreck and Manta Ray School | Undersea Ruins Adventure

A dynamic underwater exploration scene where schools of fish and manta rays circle a sunken ship.

Sunset Shipwreck and Manta Rays | Sunset Treasure

A romantic underwater background illuminated by sunset light, perfect for treasure-hunting scenes.

Deep-Sea Shipwreck with Glowing Jellyfish | Mysterious Night

A story-rich, mysterious underwater background where jellyfish glow softly in the darkness.

Blue Sunken Sailing Ship and Coral Reef | Undersea Fantasy

A beautiful and ruin-like scene where a sailing ship rests on the seafloor amid coral, lit by gentle light.

Sunset Sunken Sailing Ship and Coral Reef | Golden Ocean

Golden light warmly illuminates the ship and coral, creating an emotional underwater moment.

Sunken Sailing Ship Sleeping in the Deep Sea | Night Ocean Blue

A fantastical night scene of a quiet shipwreck resting on the deep seafloor under moonlike light.

Sunlit Seafloor Ruins and Sailing Ship | Aqua Light Blue

A bright exploration-ready scene where sunlight pours in from above, making ruins and coral shine.

Sunset-Colored Cove with a Sunken Ship | Sunset Undersea

A romantic underwater background where orange light reveals the silhouette of a shipwreck.

Midnight Shipwreck and Coral Reef | Deep Sea Blue

A mysterious night seafloor scene where shafts of light illuminate a silent shipwreck.

Sunlit Underwater Cave | Blue Cavern

A magical underwater cave scene where light streams through rock openings.

Sunset Underwater Cave | Sunset Cavern

A calm and gentle underwater cave bathed in warm light, evoking a quiet afternoon at sea.

Nighttime Underwater Cave | Moonlight Cavern

A mysterious cave scene where pale blue light filters down, hinting at the start of an adventure.

Sunlit Seafloor Arch | Aquarium Gate

A fantastical background where clear light surrounds a stone arch, reminiscent of an underwater city entrance.

Sunset Seafloor Arch | Sunset Gate

A beautiful underwater scene where golden light illuminates the arch and seafloor, leaving a quiet afterglow.

Moonlit Seafloor Arch | Deep Ocean Gate

A dreamlike underwater background where an arch glows in the silence of the deep sea, suggesting the gateway to an adventure.

Using These Assets in copainter

Create Variations with the AI Assistant
Download the images and import them into copainter as reference images. You can easily change the time of day (morning / evening / night), replace skies, or add props.

Upscale Beyond 4000 px with the Upscaling AI
Increase resolution to sizes suitable for most projects using the Upscaling AI.
https://www.copainter.ai/ja/upscaling

Convert to Manga-Ready Backgrounds with the Inking AI
Use the Inking AI to simplify lines and create manga-friendly backgrounds. Adjust pen styles to add originality.
https://www.copainter.ai/ja/inking

Adjust Aspect Ratio with the AI Assistant
If the illustration doesn’t match your required aspect ratio, you can instruct the AI Assistant to resize it.

License Terms

• Eligible users: copainter subscribers
• Permitted use: Free and commercial use allowed only for works created using copainter
• Modifications: Allowed (cropping, redraws, color changes, vectorization, etc.)
• Credit: Not required
• Prohibited: Redistribution or sale of the assets themselves, claiming authorship, commercial use outside copainter
• Disclaimer: The provider assumes no responsibility for any damages resulting from use of these materials.

FAQ

Q. I want higher-resolution materials.
A. Use copainter’s Upscaling AI. You can upscale up to 4× in both width and height, making it suitable for commercial use.

Q. Can I use these outside copainter?
A. If you are a copainter subscriber and use them for works created using copainter, commercial use is allowed and free of charge. Edits using external services are also fine as long as the purpose is to use them in works created with copainter. As long as copainter is used for some part of the production process, it is allowed.

Q. Can I use these in commercial projects?
A. Yes, if the work is produced using copainter, commercial use is allowed. You do not need to create the entire work solely with copainter. Redistribution or resale of the assets themselves is not permitted.

Q. Are there other free pose collections?
A. Yes. Please refer to the following:
https://blog.copainter.ai/tag/assets-en/

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You can find copainter Learn, our media hub packed with tips and best practices for using copainter effectively, at the link below.