Hi there Bob,
The most surefire way to get at the anchor locker drain is to remove your anchor and rode (put it on the dock). That way you will have complete access to the bottom of the locker and can see what material is clogging up the line and what else is there that should be removed before it finds its way into the hose. Once you have done that, remove any debris on the drain opening and gently send some water down it using the spray nozzle on your water hose. That should flush out any debris through the drain hole that you can see on the bow below the bow eye. If that doesn't work, you can shoot some water from the hole at the bow upward through that hose and into the locker. That should get any remaining debris. If that still doesn't work, then you can use a piece of stiff wire or similar to get the drain cleared of any remaining debris. Then just hose it down to get it nice and clean afterward. Hope this helps.
Cheers,
Ralf