Complex sentence: The arm is now known as the Prees Branch of the Llangollen Canal, and is navigavable for about a mile to Whixall Marina, the following 3/4 mile is still followable on the towpath as it passes through Prees Branch Canal Nature Reserve.
Split into simpler sentences: The arm is now known as the Prees Branch of the Llangollen Canal, and is navigavable for about a mile to Whixall Marina. The remaining 3/4 mile is still followable on the towpath as it passes through Prees Branch Canal Nature Reserve.