Abstract: In a system for obtaining core samples from a submerged bottom a core barrel and holder assembly attached at its upper end to a cable is dropped through the water from a floating vessel, and after the barrel has penetrated the submerged bottom a winch on the vessel is operated to raise the assembly into a guide tube carried by the vessel in an over-water position. An operator on the deck of the vessel swings the barrel through a vertical slot in the guide tube and as the cable is released slowly the barrel is guided to a near horizontal position so that the core sample can be removed from the barrel. The holder tilts within the guide tube during this operation but is prevented from passing through the slot, thereby preventing the assembly from swinging as a result of wave action on the vessel. The system can be used to take samples while the vessel is being propelled through the water and during rough weather.