However, if additional safety is given there is compensation for this delay when the risk is great.

One danger of a convoy system under modern conditions should be mentioned, viz.

the increased risk from attack by mines.

If ships are sailing singly a minefield will in all probability sink only one vessel--the first ship entering it.

The fate of that ship reveals the presence of the field, and with adequate organization it is improbable that other vessels will be sunk in the same field.