Not until there's a natural obstacle between us and that other ship.

However, it also pointed out that serious natural obstacles would have to be overcome.

The main rule states that people and things constitute natural obstacles on the path.

The city grid is mostly filled with natural obstacles at first.

The river presents natural obstacles in the form of light rapids.

There are no trees or natural obstacles near the track.

By June 16, there were no further natural obstacles in front of the American forces.

Their direction, making allowances for natural obstacles, led directly to the lake keep.

There are natural obstacles on both sides that narrow down towards the English.

First, an attempt was made to clear the natural obstacles, but that proved too expensive.