I agree with Doombeagle here... This to me is the essence of contesting a cap. You don't have to take it right off, you can be effective for your team simply by being there sneaky like, then punking the unwary, taking the cap back once the opposition moves on or poking the edge of a cap (with an escape route close at hand) in order to bait CA's to pop off their radar. You can also transition into herding mode, dropping torps or showing yourself very briefly, to get opfor capital ships to move away from you into the line of fire of others or to chase you and pull them from the main fight. If you are not divisioned up.. watch the flow of you team and adjust what you are trying to do. play the screen on the weak flank and slow down advances there.. get out in front of a push and screen/hunt DD's in front of that. And above all, keep in mind that in absence of a CV, a DD has the most influence on the outcome of a game once you are past the mid point, So be aggressive early but don't be rash. Don't try to force things to happen. Keep your situational awareness on high (location/range of radar, location of other DDs, etc) and leave yourself a way to quickly disengage and re position for better opportunities.