how are bathymetric maps made? if i go to google maps i can see the ocean floor in low res - is that done by satellites? i remember trying to find data of a pa

how are bathymetric maps made? if i go to google maps i can see the ocean floor in low res - is that done by satellites? i remember trying to find data of a particular area (near azores) using NOAA maps and all i found was some sort of compendium maps made by different vessels across the years mashed together in a hodge podge of resolutions life sounds rough for ocean floor researchers lmao