Whenever my ball goes into a concrete drainage ditch, I check the scorecard for a local rule. Sometimes courses give free relief from a man-made drainage ditch (Twin Oaks comes to mind). At Mission Trails, the scorecard indicates that they are treated as a lateral hazard.
That's all well and good, but can I get relief for my stance if my ball is not in the penalty area, but the concrete drainage ditch impacts my stance or swing?
Rule #17.3 is very clear that you do not get relief from an abnormal course condition if your ball is in the penalty area. But I couldn't find anything explicit in the rules about getting relief when the ball is not in the penalty area.
So my interpretation is that you can take relief from a drainage ditch if your ball is not in the drainage ditch, but the ditch interferes with your stance or swing. I could be wrong?
Two related rules that I often see people get wrong:
- Taking relief from a boundary fence. If an internal fence interferes with your stance or swing, then you are entitled to free relief. This is not the case for a boundary fence (Definition of Boundary Object)
- Obstruction interferes with line of play. If it's not interfering with your stance or swing, you don't get relief (Rule #16.1a). You do get relief for this on the putting green.