Hey BatRay (edited - don't where I saw the previous name I wrote),
(my first post - hurray!)
Whilst I haven't freedived or spearfished there myself (much as I'd love to get the chance - I'm new to the sport), I am from Argyll and also previously worked for a company with a dive team who gave me a few tips.
There is an area just off Carradale at NR 82013 37592 where line fishing for mackerel and pollock can yield a good deal. You can park in front of the nearby hotel and get there by walking along the narrow coastal path. My family and I caught 20+ mackerel, a dogfish, a pollock and a cute wee octopus there last weekend (we released the dogfish and octopus). We fish off this very noticeable vertical spike of rock, beneath which is a quick drop in depth, only a little kelp/seaweed and a nice sandy bottom. We always see seals and gannets diving there so in addition to our catch it must be a sign of healthy marine life. There is also a herd of wild goats nearby who might say hello.
One of my former diver colleagues also said that you can pick up lobster in and around the outfall of the marine lab at Machrahanish. He said also to watch out for the currents particularly south of there as they can be very so strong. A surfer was blown out to sea from Machrahanish Beach recently and rescued after 36 hours, and the exact same thing almost happened to my friend who was kayaking (he swam to shore but lost the kayak!). Basically, the east coast of Kintyre is notably calmer and more sheltered than the west.
If ever you're planning an outing and looking for a dive buddy in the area, feel free to let me know!
