SONAR, satellite radar, GPS, and deep-sea diving vessels all contribute to accurate MEASUREMENT of the depth and motion of the sea floor, and of the motion of the continents.
Once the measurements are known, they can be analyzed to determine whether OR NOT they support the idea of continental drift, or some other hypothesis.
Real scientists don't go out looking for evidence to support the ideas that they want supported. That kind of approach to research is found more in the Flat Earth department.
