Bathymetric Survey

What is bathymetric survey means? I just google it and found that bathymetric is a study of under water depth of lake or oceans floors. Meaning that bathymetric is the underwater equivalent to hypsometry or topography. 

My Honda Brake Pad

My honda rear brake pad wore at 30,000km and I already replaced it without concrete justification from Honda Service. I am very dissapointed when they said that they don't know why. Did they hide something from customer? 

Honda rear brake pad original cost me around RM450+. Anybody had same issue with new accord car? Premature wear and tear.