Sorry to hear about your job... that seems to be happening a lot lately. Hang in there. Better things to come.
How far are you travelling to get to Tobermory? (i.e. approx where are you from?)
I checked out Google maps and you're right, Halfmoon does look a little more hospitable than I described from Sailing Directions although still not much of a place. It shows on the charts as only 12 ft elevation.
Regarding distance to the horizon... there are tables that can assist you with this. The tables are sometimes reproduced on charts or in chartbooks like Richardsons (large enough to sink your kayak by the way). Here is one link with the tables. Distance to The Horizon
Unfortunately, these tables are in metric and although I am a proud citizen of a metric country, meters and kilometers have no place in nautical measurements in my humble opinion. Give me my boat speed in furlongs per fortnight before you give it to me in kph. ... OK, end of rant, back on track...
For example, lets say you are sitting in your kayak and your eyes are 1m above the water. From the table, distance to the horizon is 3.7km. You are looking for Halfmoon with an elevation of 12 ft which is approx 4m... table shows 7.4 km. So all things being perfect, you would be able to detect Halfmoon island at 3.7 + 7.4 = 11.1km (or 6 nautical miles). Better yet, Lonely island is approx 200 ft (61m) high. Lets say 60m .. From the table, distance to the horizon is 29km. So if you know where you are looking and what you are looking for you should be able to detect Lonely Island at 3.7 + 29 = 32.7 km (17.6 nm) Remember, these distances are to the very top of the tallest feature that you are looking for on the island and you may not recognize it as such until you are closer.
"I was sure that because i was a sea kayaker not a sailor with nice boat I wouldn't get anything but a laugh and a get lost punk attitude."
I had to laugh at this. All boats are nice (except maybe cigarette boats and PWCs). A nice boat is one you are on at the moment. If you are looking for a "get lost punk" attitude, try the Off Topic forums!
Keep the questions and comments coming.