We travelled as a party of four and spent 2 nights in Istanbul before the cruise. Booked all elements independently and had good connections via Lufthansa both ways via Munich. Stayed at Erboy Hotel and would highly recommend - they even arranged to collect us from the airport (which can be chaotic) for €25 which we paid to reception on arrival.
After two days sightseeing we caught a taxi to the ship for 20 Turkish Lira (£7.50) and arrived around 12.30pm
Embarkation was a breeze and we were on board within 10 minutes of arrival.