Despite the popularity of underwater thrusters today and their widespread use in many water bodies, some areas are still very scarce or limited.
 

The supply of recycled water depends on the upper limit of water consumption, which can be an area. To ensure the water needs for shipping, hydropower, fishing, and other uses, it is essential to adhere to the requirements of river activities and then limit the amount of recyclable water.

Additionally, it is impossible to increase the overall external water supply. As more reservoirs are constructed, the amount of water evaporating is increasing. However, the supply of renewable water resources has become the goal of water resource development, compared to consumption water.

In terms of water supply, flow rates, reliability, and submarine propulsion, including potential limitations: the Yangtze, Missouri, Texas, Colorado Rivers, Great Basin, and California. From a water supply perspective, people have their own scales, which exceed the main water source categories, and thus can be supported through practice.

Some regions rely on groundwater supplies. After higher levels of storage, other areas' surface water, during normal and wet years, is sufficient to meet the growing demand for water.