Any good strong knot will do to attach the rope to a 'hard point' .... one of the best knots to use for this would be a doubled figure-of-eight with a loop and then 'cow hitched' to a rail or other hard point, etc. http://www.animatedknots.com/fig8fol...matedknots.com
Animated Knots by Grog | How to Tie Knots | Fishing, Boating, Climbing, Scouting, Search and Rescue, Household, Decorative, Rope Care,
I'd recommend against 'coiling' a line ... as surer than hell ... one or more of the coils will get twisted and tangled and can/will cause a time-consuming 'mess' (birds nests, etc.), especially when time is vital.
Rather than coiling, Id recommend that you store the rope in a 'throwing bag' ... in your case on a boat you throw the ring
and the line automatically pays out of the bag attached to the boat. 99.9% of the time the rope pays out 'straight and tangle free'.
All rope throwing bags should have a grommet hole in the bottom of the bag through which you pass the terminal end of the rope which is tied/knotted to some hard point, etc.
If you're handy you can sew-up your own bag (out of 'Sunbrella' which is UV stable and long-lasting in the marine environment; or, purchase one at a 'climbing' shop or 'mountain' shop but since a 'store bought' will be NYLON
fabric, wont last long
in constant sunlight/UV exposure: NRS Standard Rescue Throw Bag at nrs.com
You can easily practice or do a 'preliminary trial' with a throwing bag before you make your selection on the size of a throwing bag needed .... just take your line, stuff it
haphazardly but compactly and as 'tightly' as possible into any moderate sized nylon, etc. bag, (12" diameter X 18-24" long will probably do for the typical 100ft. of 'rescue' line) etc. and do some trials by stepping on the excess line that doesn't fit into the bag, and simply 'throw the bag' (or attached ring while hold your foot on the 'tail' of the rope) as far as you can. Do this a few times and you'll quickly and intuitively be able to arrive at the proper throwing bag dimensions you'll need.
How to 'load' a throw bag.
... the use of a 'throw bag' AND with the additive use of (non-tangling) 'butterfly coils'
Doing your sailing on 'the Rock
' ... most definitely you'll need to do a FAST rescue. :-)
hope this helps. ;-)