not sure about a ramp down colington road except inside the gates and the harbour leads into the sound.
If you come out of col. rd and head north make a left beside Belk Tyler,3rd street.go to end and make a right.ramp is on the left.
you can fish for trout,flounder,puppies.
crabbing is done from the bridge walkways on Colinton rd.
hope this helps.