Just finished installing hds7 and structurescan on boat. When I power up, and select structure, it only displays centerline, but is blank on either side of line. Would I be correct in assuming that it is because boat is not in water?

Yes.

Sometimes you can get sonar returns with 2D sonar through air off a hard surface close to the transducer, but not with the high frequencies of the imaging technology.

Yes.

Sometimes you can get sonar returns with 2D sonar through air off a hard surface close to the transducer, but not with the high frequencies of the imaging technology.

Thanks Wayne!