Draft safety learning material

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VISUAL GUIDESeparate three kinds of movement
Wind: moving air. Wind acts on bodies and equipment exposed above water.Air moves

Wind: moving air

Wind acts on bodies and equipment exposed above water.

Waves: a travelling disturbance. Wave direction is not necessarily the direction of drift.Wave shapes travel

Waves: a travelling disturbance

Wave direction is not necessarily the direction of drift.

Currents: moving water. Water moves in currents, including rip and tidal currents.Water moves

Currents: moving water

Water moves in currents, including rip and tidal currents.

Each panel is a separate example. Arrows do not describe the conditions at one place, speeds or drift paths.
TAKE THIS WITH YOUConsider wind, waves and currents separately, and check local instructions.
01

Three related but different movements

The appearance of waves cannot tell you how something will drift.

Wind is moving air. Waves carry a disturbance through water. A current is the movement of the water itself. They interact, but they are different phenomena.

A floating person or object is affected by wind on the parts above water, as well as by currents and waves. Wind direction alone cannot predict the object’s actual route or speed.

Go deeper: is all offshore drifting a rip current?

A rip current is water flowing away from the nearshore area. An offshore wind can also push an inflatable away from land. Moving offshore does not, by itself, identify the cause. Think separately about air and water movement.

Sources: [1] [2] [3]

02

Wind from land can push inflatables out

VISUAL GUIDEWhich way is the wind blowing?
Offshore: land to sea. Wind can push an inflatable away from shore.SeaLandInflatable

Offshore: land to sea

Wind can push an inflatable away from shore.

Onshore: sea to land. Waves, currents and coastal terrain can still pose hazards.SeaLandInflatable

Onshore: sea to land

Waves, currents and coastal terrain can still pose hazards.

Viewed from above. Arrows show air movement only, not an inflatable’s path. These are not ‘safe’ and ‘unsafe’ categories.

Being close to shore does not remove the effect of wind.

Here, offshore wind means wind blowing from land towards the sea. Swim rings and other inflatables can be affected by it, especially tall or bulky toys with a large area exposed to the wind.

The Japan Coast Guard advises keeping hold of an inflatable carrying a child and avoiding its use in strong wind. A swim ring is not a substitute for a correctly fitted life jacket. Check the site’s equipment rules too.

Go deeper: is wind towards land safe?

An onshore wind does not remove hazards from waves, currents or terrain. Neither ‘onshore’ nor ‘light wind’ is permission to swim.

Sources: [1] [2]

03

A north wind comes from the north

VISUAL GUIDEThe same north wind, two different coasts
Sea to the north. From sea in the north to land in the south: onshore here.NSSeaLandNorth wind

Sea to the north

From sea in the north to land in the south: onshore here.

Sea to the south. From land in the north to sea in the south: offshore here.NSLandSeaNorth wind

Sea to the south

From land in the north to sea in the south: offshore here.

North is at the top in both maps. Wind moves from north to south. Terrain effects are omitted; these examples do not predict local wind.

Read the wind direction, then look at which way the coast faces.

Weather reports name wind direction by where it comes from. A north wind moves air from north to south. Its relationship to the shore is reversed when the sea lies north of the land instead of south of it.

The diagrams compare directions only. Headlands, bays and nearby terrain also affect local wind. Check the place and time a forecast or observation refers to, and follow local guidance.

Go deeper: average wind and gusts

JMA normally reports wind speed as a 10-minute average; instantaneous wind speed is a 3-second average. Wind varies during that time. An average is not a constant speed you can expect at every moment.

Sources: [4] [5]

04

Check, observe and change your plans

One wind-speed number cannot decide whether to enter the sea.

Before leaving, check current wind, wave and warning information for your destination and visiting hours. Swell can arrive from far away, so do not judge conditions from a sunny sky or light local wind alone.

On arrival, check whether swimming is permitted, read signs and listen to lifeguards. Agree to stop if the sea or someone’s condition changes. This lesson does not replace practical swimming or rescue instruction, or training for activities such as stand-up paddleboarding.

Sources: [1] [2] [3]

LET’S THINK

A question to explore

The forecast says ‘north wind’. At a coast with the sea to the south, does that wind blow towards land or away from it? Is that enough to decide whether you can swim?

Show a hint and explanation

On this simple map, it blows from land in the north towards sea in the south: offshore. Real wind is also affected by terrain. Either way, wind direction alone cannot establish whether swimming is permitted or safe. Check waves, currents, official updates and local instructions.

Explore together, at home or in class

Place a north-to-south arrow over a map, then swap the sea and land. Explain that the arrow shows air movement, not the path a person or inflatable will follow.

Sources & further reading

We developed our own explanations and diagrams using these sources. Inclusion does not imply review, endorsement or affiliation by the source organisation. Links marked “Japanese” lead to Japanese-language material.

First published: 2026-09-20 · Updated: 2026-09-20 · Sources checked: 2026-09-20 · Editorial policy