Hmmmm. While this approach seems neat in theory, it would worry me in practice, especially in the Greek and Turkish harbours we often frequent. Often, the mooring
lines are not neatly continuous but joined somewhere along their length with a big knot
that could jam your hook halfway along and leave the mooring line at just the right height to foul your prop. Also, it's not that unusual to have to abort in strong wind
conditions and make a new approach - not easy if you've meanwhile had to release the bow end of your 6mm line (because you can't retrieve the hook) and it's now lying right across the harbour.