To attack strongly, whether by force, question, word, or doubt. Not explicitly included: naval warfare. You can assail someone using a sailing vessel but it's not necessarily an assailant. (Unless you're telling a tale to someone, and in that case, EVERYTHING WAS ASSAILING YOU. YOU ARE A WARRIOR.)
I know it's Monday but let's do some math, mmkay?
500 meters is 1640 feet. That's three-tenths of a mile, and more than four football fields (plus endzones laid end to end).
A little over a week ago, Theo Sanson walked this distance—in the air—over a canyon—on a slackline:
As the video states, the rigging of the line is perhaps even more impressive than the walk itself. How would you make a rig that secure for that kind of angle and then connect it to the two pillars? And even if the rig was secure, why would you get out there and try to walk it, knowing you're going to be so, so tense for such a long walk? Goodness. What an incredible feat, and not one I want to do.
VideoWalksUtahDronesSlackliningStep by stepDon't look downCareful, careful