### L222 How Sounding Works > Tom took a chunk of heavy grease and packed it into a cavity in the bottom of the lead weight. I cast the line, called out the sounding, and then pulled in the line and looked at the residue from the bottom trapped in the grease. An expert like my skipper knew the seated deposits so well, he could tell roughly where he was. In this way, we felt our way inshore on a day when the visibility was less than a mile, using the five- and ten-fathom lines and the samples from the bottom as our guides. - [[Beyond the Blue Horizon by Brian Fagan#L222 How Sounding Works|View in Vault]]