Getting from Pattaya to the pier from which ferries and boats depart for Samet Island (sometimes called Samed) takes about an hour and a half to two hours. From there, it’s about 20 minutes by boat, and you’ll find yourself on the small (approximately 7×13 km) beautiful island of Kon Samed. Video:
Sai Kaew Beach

It should be noted that there is at least one more Sai Kaew Beach in Pattaya. Probably means something popular or common. This happens in beach countries — you often come across names like Palm Beach, Butterfly Beach, Sunrise Beach, Blue Lagoon Beach, and so on.