Hi Jim, Basically no.. it's hard to explain.. It''s (I believe) because the way it's done the longer side ropes don't really get any tighter as the boat goes down (Think of a bridge onto a floating pontoon..The bridge is the same length on high and low water.. it slides back and forth although it only slide back a forth a little), so although you shouldn't do them very tight (I'd leave the normal slack) then you don't need to worry (Unless it's a huge rise and fall then you add more slack), but it's still tight enough to stop it moving back or forward other than a foot or so (which is just the bit of slack rope).. So n less tidal rivers (So the upper reaches or the northern rivers) you can reduce that slack so the boat will hardly move back or forward... Hope I've kinda explained.. I'd say have a practice and you will hopefully see what I mean. (Hopefully someone can explain further )