Sailing around Greek Islands (Athens)

Hi, I'm a InterNations Member in Sydney. My wife & I in Greece region mid Sept to mid Oct Protected content . Trying to find a small boat charter company (up to approx. 50 people size) that may offer tours around the Greek Islands. We don't enjoy larger cruise ships. Looking at maybe 7 to 10 days. Doesn't have to be 5 Star. Just a smaller group having fun. Protected content . Thanks, Kerry