A water diya, also known as a "water lamp" or "floating diya," is a traditional Indian oil lamp used during the festival of Diwali and other auspicious occasions. Unlike the more common clay or metal diyas that are filled with oil and have a cotton wick, water diyas are made by placing a small amount of oil or ghee (clarified butter) on the surface of water and lighting it.

Here's how you can make a water diya for Diwali:

1. Take a shallow bowl or a small container and fill it with water. Make sure it's not too deep; a few inches of water are sufficient.

2. Add a teaspoon of oil or ghee to the water. Ghee is commonly used because it burns cleanly and produces a bright flame.

3. Place a floating wick in the center of the water-oil mixture. Floating wicks are readily available in the market and are specifically designed for water diyas. These wicks have a small cork-like float at the bottom to keep them afloat.

4. Light the wick using a matchstick or a lighter. The wick will start to burn, and the flame will gently dance on the water's surface.

5. Arrange multiple water diyas in a decorative manner, either indoors in a shallow tray or outdoors in a pond or container of water. They create a beautiful and serene ambiance, especially when used in the evening during Diwali.

Water diyas are not only aesthetically pleasing but also hold cultural and spiritual significance. They symbolize the triumph of light over darkness and are used to welcome the goddess of wealth, Lakshmi, into homes during Diwali. Additionally, they are a more eco-friendly alternative to traditional oil lamps as they use less oil and create less waste.

Remember to exercise caution when using any kind of open flame, and never leave diyas unattended. Safety should always be a priority during celebrations like Diwali.