Complex sentence: The Master of the "Francis" reported, to Colonel Collins, having seen smoke rising from one of the islands in the Kent Group and this raised concerns over the safety of the "Lady Nelson" which had not yet arrived at Port Phillip.
Split into simpler sentences: The master of "Francis" reported to Colonel Collins having seen smoke rising from one of the islands in the Kent Group. This raised concerns over the safety of "Lady Nelson", which had not yet arrived at Port Phillip.