So, this is kind of how a day went on top of Kartepe on the 27th February 2011:

Arrived in Masukiye town at the bottom of the hill, just off of the O-4 highway, where we had breakfast in a cafe. Borek and Pogaca's with tea. There are several ski shops which have skis and snowboards/equipments for hire and to buy.

The one we found had skis/poles/boots/goggles package to rent for 25TL.

Make sure you have a set of snowchains in your car, the Jandarma will check to see if you have any, although, the road was completely ploughed and gritted, so no need for them anyway. When we got to the top of the hill, a guy standing by the entrance sold us a parking ticket for 5TL, and then we drove around to the right and parked up (on a day trip, there;s a sign which says "gunubirlik otopark"). When we parked, we found it was quick just to put on our gear next to the car, and then walk down to the hut which sells the ski passes. For an unlimited pass, it costs 75TL, there are lower prices for 5 or 10 times on the lifts. We paid with debit/credit card.

We went down the slope to the bottom where all the lifts are, then started our day from there.

Positives: Nice place, with lots of trees and good scenery. The runs are great for beginners (providing the weather is good), and there's a bit of choice, so intermediate skiers should be entertained for a whole day.

No 10 piste is a longish, pleasant run (rated as a blue, which is about right), there also some off piste parts to explore around the whole area.

The Green Park Hotel runs the resort, and is right next to the slopes.

Two negative points: Queue jumpers at lifts (flipping annoying), and also the chairlifts are not that well run, stop/start and sometimes closed with no clear reason for 10 minutes or so. Not really worth 75TL, more like 40TL, but hey, it's still fun to go there!