Penalties at the 40' line

We're still boat searching.  It has slowed down considerably - and as we continue to narrow our window on brand and model, the key question has become length.  

Here's where I need some help.  We're shooting for a 38' + size, but I've read snippets here and there about increased fees for docking, customs etc.  But that's just it - only snippets.  Hints at higher costs, but no concrete evidence.  So I'm on the prowl for information.  Is it true that something magical happens after 39' and that we should be charged accordingly?  Should I stick to searches for 38' and 39' catamarans?  Or is it just more boating folklore floating around on the web?

If it's true - that certainly narrows my searches and helps me focus.  If it's just another tall tale of the seas, well, I'd entertain the possibility of another few feet!

 Cat haulout   Image from Cruiser's Forum 

*The longer the boat is, the wider it is - the longer and wider it it, the more it costs to haul out of the water!  And once you hit a certain (TBD by more research) width, it seriously limits your choices of marinas throughout the world.