First let me say we gave this 'company' every opportunity to address our complaints but they first ignored us, and then threatened us once we starting posting reviews. Clearly customer satisfaction is not required as there are plenty more tourists in the sea, so to speak.
Let me assure you the pictures you see on here, Facebook, Viator etc are not accurate. Because of this deception it's fair to assume that some positive reviews will be fabricated too. The large white boat with cover seen in all their advertising is not used - only small, exposed rubber dinghies. Likewise the wildlife you see pictured is not present, nobody in our group witnessed a single living creature while at sea.
Our biggest problem with this 'experience' was the boat. This was the second day of our holiday and we were white as sheep. Without any form of cover we were completely exposed to the blistering sun for hours, and as such received sunstroke and second degree burns. We couldn't even wrap ourselves in a towel as we were told to lock them in their storage box before departing. Because of this, the rest of our holiday was completely ruined. We had to cancel all the other plans we had and stay in our hotel until such time we could fly home to see a doctor.
As if that wasn't bad enough, even the 'experience' itself was complete rubbish. They simply took us out in their toy boat, strapped some flippers to us and dumped us overboard. The 'instructor' (who didn't speak English) did nothing but swim away from us saying 'come, come'. After a while of following him we released we were so far away from the dinghy we couldn't even see it any more, which caused real panic as we were not very strong swimmers and knew it would take all our energy just to get back. We even told him we were in trouble but he just shrugged and swam away.
If this isn't enough to put you off, the available 'snacks' they mention on their advertising are literally breadsticks and water.
Essentially their advertising is false which is illegal.
Based on our time with Chania Diving Center they are dishonest and dangerous, and we cannot advise strongly enough that you avoid.