The story didn't end well ?

From what i can find during a quick google search, it seems there's no set distance except with regards to navy vessels. But it seems that most agree the minimum between vessels should be 0.7 Nm, with many people saying they consider 1 Nm to be the minimum safe distance.

If you're close enough to use a grappling hook , the minimal distance is 0

Everything went fine, it was more comical than anything else. I'm sure the freight companies didn't enjoy it because I guess in that business ahead of schedule, on schedule, and behind schedule can mean a difference of millions in terms of revenue.

wouldn't that varry depending on the ship type and their speed? I mean the safe distance between two 20m long sail boats sailing at 5 kts is probably around 60m, whereas the one between two supertankers speeding at 20 kts would be closer to a full nautic mile...

Yeah, this is why i don't think there's any real set minimum. But yes, that's exactly it. The bigger the vessel, the more the Bernoulli Effect kicks in as well, which tends to draw the ships together. So there are a number of factors at play. In the end, I think it really comes dowb to the captain's expertise.

What I find interesting is how everyone seems to have assumed these were ocean bearing ships. My assumption was that they were spaceships such as X-Wings or Tie Fighters and I was going to suggest that regulations vary between the Rebel Alliance and the Empire over this and that it is actually one of the underlying strong minded controversies that started the Star Wars to begin with! :)

The 1999 movie , Wing Commander, offers us a , Humm, "precious infomation" on the distance to be observed by spacefaring "ships" : ships would travel as close as possible and distance would solely be estimated by educated guesses made by the most senior officer on the bridge, based on his/her immense knowledge and his/her ability to instantly resolve complex calculations... only found it in French but anyone can get how important the measurement of distance is in this movie : http://www.dailymotion.com/video/x4jqj_wing-commander-film-attaque-ennemie_shortfilms