Dimensional lumber is for construction: 2x4, 2x6, 4x4, etc. Black locust makes great deck(or dock) construction wood. Now if you wanted some great outdoor furniture you would not cut it to dimensional sizes. You would ask to have it cut into the thickness you wanted and sawyer would try to maximize the board width for that thickness. These sizes are 4/4, 6/4, etc. and represent the inches by the 1/4". 4/4 is one inch, 6/4 is 1-1/2". You end up with more wood, but would need to rip them down to the sizes you need when use them. My local sawyer charges $90 and hour(a bit high) and cut 2 of my trees in 45 minutes. The same wood would have cost me about $250 at the big box stores. I attached an image of a proper girdle. I may be new to ponds, but I know wood.
