UMIMORI / OUR BLUE CLASSROOM

Know more. Prepare together.

A calm-looking sea can still have currents. Conditions change, so preparation continues after you arrive.

Your day by the sea

Water carried towards shore collects and flows offshore in a rip current.OffshoreShore / beachRip current flowing offshoreOne example, viewed from above
Compare waves and currents

One simplified flow pattern. Real conditions change.

START HERE

There is more to the sea than you can see.

Waves, currents, wind and terrain all matter. Start with an officially managed swimming beach, and check its designated area and local instructions.

Understand rip currents

Three moments to check.

01

Before leaving

Check beach opening information, weather, warnings, equipment and everyone’s health.

02

On arrival

Check swimming areas, flags, signs, lifeguard instructions and evacuation routes.

03

During your visit

Stay close to children. Notice changes in the sea and how people are feeling. Be ready to stop.

Open the checklist →

Check official information.

Sources checked: 2026-09-20. This site does not assess local swimming conditions. Safety material is awaiting specialist review.

Understand the conditions.

Arrows show wind blowing from land towards the sea.SeaLandInflatable
Coastal safety

Wind, waves and drifting offshore

Explore the lesson
Water carried towards shore collects and flows offshore in a rip current.OffshoreShore / beachRip current flowing offshoreOne example, viewed from above
Coastal safety

What is a rip current?

Explore the lesson
Water level and the shape of the coast.Sea levelExample high-tide levelAn imaginary coast, viewed from the side
Ocean science

Why do tides rise and fall?

Explore the lesson

VISITING JAPAN

New to Japan’s coast?

Local planning tips, useful phrases and where to get help.