Underwater rock boring apparatus having differential global positioning system receiver and boring method thereof

A boring method using an underwater rock boring apparatus having a differential global positioning system (DGPS) receiver comprising:

• a) an initializing set-up step comprising the substeps of:
• moving a barge that has the boring machine with the DGPS receiver on the center of the barge above the rock to be bored;
• anchoring the barge by operating plural winches and plural wire ropes to drop the anchors on the rock that is far away from the hull at a predetermined distance to stop the barge;
• the controller receiving the present position data of the barge from the DGPS;
• establishing on the display means the XY plane with the origin of the present position;
• storing the boring map and the boring data in the boring data memory means to display the target boring position of the underwater rock on the display means;
• b) displaying the target boring position oriented from the boring data memory means and the position of the boring machine inputted from the DGPS on the display means with the XY plane;
• c) determining whether or not the position of the target boring corresponds with the position of the boring machine;
• d) when the position of the boring machine does not correspond with the position of the target boring, the controller driving the winch driver to move the hull;
• e) when the position of the boring machine does correspond with the target boring position, lowering the rod and the bit of the boring machine through the opening of the barge and boring the underwater rock;
• f) when the rock boring work for the target boring position is completed, moving the hull to the next target boring position;
• and wherein the above steps b)˜f) are repeatedly performed.