tried this but there's no boat at Lor'denal.... waiting nothing. even looked as an alliance character and the boat just sits at Rut'theran.
going through SW is very hard with alliance and 85 guards. the worst part I got to Rut'theran got the one in Darnassus and went back to take the Exodar one but of course guards kill me in Rut'theran. then I have to corpse run from Dakrshore through the fatigue. I get to Rut'Theran and look at my body but I can't rez, it tells me my corpse is in the ocean somehow.
Unfortunately, you can not just swim from Lor'Danel to Rut'Theran. You have to be able to run across the water while mounted with either path of frost, water walking from a Shaman or water walking potion. If you swim you'll die of fatigue. The guards also cause some problems as they are now 85 elites and fire bows at you. I died running into Darn and died a second time coming back out. If you die on Rut'Theran you res in a grave yard in Darkshore.
It's totally doable (just got it done yesterday). You need to go to Rut'Theran.
I tried getting water walking from a Shammy in Org, flew to the farthest west FP in Ashenvale, and ran like hell to the most northwestern point of shallow water in Darkshore. I messed up and took some fall damage, completely getting rid of the water buff. I used a swift swimming potion, and I almost made it to the island. Exhaustion kicked my ass though, but that only means you have to run back to your corpse and try again. Didn't die a second time. The boat is on the left side of the island, and I really recommend taking that before attempting Darnassus.