getting off the berth

One of the challenges that I haven't yet mentioned is that my berth is on a finger pontoon that is at about 45deg to the main pontoon..... Splendid i hear you cry... dead easy to get onto... and yes you are right... its even port side too, so with a slight kick to port astern its really very easy to go in nice and tight and tidily..... However the challenge lays in the fact that the next row of berths are really quite close, and i'm still not sure yet how well she go in a straight line astern when under way..... with the rudder very far back, and a fin keel, I suspect that she'll want to turn rather than go in a straight line...... So my plan is to pull off under power, but leave a running stern line, and at the last minute choke the stern line to pull the back end round a little, and voila, I should be pointing in the right direction.....and if I do it gently with the stern line, I shouldn't even 'over rotate'.... But god help me if she doesn't want to continue in that direction, as there is not really room to turn her in the aisle.........cou;ld be messy.... :o)