Complex sentence: His journal entry for 29 November 1642 records that he observed a rock which was similar to a rock named Pedra Branca off China, presumably referring to the Pedra Branca in the South China Sea.
Split into simpler sentences: His journal entry for 29 November 1642 records that he observed a rock which was similar to a rock named Pedra Branca off China. This would presumably refer to the Pedra Branca in the South China Sea.