Complex sentence: South of Thebes, the "Isis" sprang leak and nearly sank, having lost many provisions and spent several days repairing the boat they continued south to Aswan where the boats had to be left, since they could not make it across the first Cataract.
Split into simpler sentences: South of Thebes, the "Isis" sprang leak and nearly sank. Having lost many provisions and spent several days repairing the boat they continued south to Aswan where the boats had to be left, since they could not make it across the first Cataract.