In the version of Famine Beach, you first need to sail in the sea to find kelp, but kelp can't be collected directly. You need to install a trawl on the boat, and then control the boat to pass the kelp, and the kelp will enter the trawl. Drive the boat to the shallow sea, put down the trawl, and then click the trawl to collect kelp and plant the collected kelp directly in the sea.