This is called the sea breeze and happens during the day. At night, the land cools faster than the sea, again because sea has large thermal capacity and does not give off heat easily. The air on the land now is cooler than the air on the sea. This time also a convective current is generated, but in reverse. This happens during the night.
Hot air is lighter and rises to the top by convection.
In a room, therefore, the exhaust fans are always placed on the top near the ceilings, so that the hot air is removed from the room. Hold your hand close to the vessel. You will feel the warmth of the vessel. Similarly, if we sit in the sun, we feel warm. The process cannot be conduction, as there is no direct contact.