What a camera contributes
Optical video can show recognizable surface detail, markings and material appearance when light and water clarity allow. Lighting position, suspended particles, standoff distance and camera control affect what the operator can interpret.
A sharp image does not automatically provide scaled dimensions. Measurement needs an appropriate reference or calibrated method.
What imaging sonar contributes
Sonar uses acoustic information and can be useful for navigation and feature recognition where optical visibility is poor. Interpretation depends on the sonar type, frequency, geometry and target.
Imaging, profiling and bathymetric sonar serve different purposes. An optional sonar interface is not proof that a particular sensor or reporting workflow has been integrated.
Why a combined package may be appropriate
Sonar may help the operator approach or find a target; the camera may then provide local visual detail. Confirm that both data streams can be recorded, referenced and interpreted for the actual defect or condition.
Ask for task-relevant samples
Request footage and acoustic data from comparable visibility, geometry and target conditions. Agree what must be detected, how it will be located and what counts as acceptable evidence.