SVK Test Model 6. The design of this model was based on the following considerati-ons:

1. The difference in light intensitiy caused by the passage of large ships (at least 1,000 tons) is greater than that caused by the motion of the seay in sunlight.

2. The sensitivity of the unit can be reduced by the addition of resistors in parallel with the I relay, so that the unit will discriminate between differences due to wave motion and the passage of ships.

3. If desired, these resistors can be switches in and out of the circuit by means of another I relay connected to a supplementary selenium cell.

A single test of this model in the Kieler Bucht gave satisfactory results in a smooth sea and sunshine. However, since further tests were not made, no further evaluation of the unit was possible.