To get there, you can take the public bus no 55 or 99A. You can even go ahead and take M7 metro to Basaksehir Metrokent and take the HAVAIST from there.The bus team explained to me which i would need to take the bus to Esenler bus station initially, just before transferring to another bus to Yalova. I compensated 125 TL (around $7 USD) for your bus