Complex sentence: At 3 AM, "Astrée" regained her place at the rear of the squadron; the weather, which had been rough, improved somewhat, and in the moonlight "Astrée" suddenly found herself at gun range of "Africaine".
Split into simpler sentences: At 3 AM, "Astrée" regained her place at the rear of the squadron. The weather, which had been rough, improved somewhat, and in the moonlight "Astrée" suddenly found herself at gun range of "Africaine".