They do make cupholders w/ drains that accept tubing on the bottom. You could potentially run the tubing from the forward cupholders to the bilge under the motor via the storage area under the front of the boat.
For that matter, you could just run the tubing to the battery box area which dumps into the bilge, if I remember correctly.
2005 ProStar 197TT, #28 of 100
Broken Bow, OK vacation cabin for rent -