Signs That Land is Nearby When Lost at Sea
When there is no land in sight you may find some of the following indicators of land and the direction in which it may be found:
Clouds: Cumulus clouds in an otherwise clear sky are likely to have been formed over land.
In tropical waters a greenish tint on the underside of clouds, known as lagoon glare, is produced by the reflection of sunlight from the shallow water over coral reefs.
Birds: A lone bird is not a reliable indication of land, and after rough weather birds can be blown way off course, but few seabirds sleep on the water or fly more than 100 miles from land. Their direction of flight is usually outwards from land before noon and return in the late afternoon. The continuous sound of bird cries is usually an indication that land is not far distant.
Watching the direction of flight of a sea bird can indicate where to find land.
Driftwood: Driftwood, coconuts and other drifting vegetation are often a sign that land is near (though they can be carried right across an ocean).
Sea movement: The pattern of the swell may indicate land. A change in its direction may be caused by the tide pattern around an island. Prevailing winds build up a swell pattern and the swell is less if the water is protected by land. If the wind is constant but the swell and waves decreasing you can be fairly certain that land lies to windward.
Sea Color: Water that is muddy with silt is likely to have come from the mouth of a large river.