Marin you say your OB boat is a sport fishing boat. What makes it "sport" and what features make it a fishing boat. Looks like just a boat to me.
I'm beginning to feel like a bloody first grade teacher here......
SPORT per Webster's Dictionary: To play in a happy and lively way.
FISHING per Webster's Dictionary: The sport or business of catching fish.
What features make this particular boat a fishing boat? Well, it's designed specifically to accommodate downriggers and rod holders, it has a large fish well and two bait tanks built in, and the designer and manufacturer, Mr. Juichi Arima, said that his intent was to design a sportfishing boat.
Now if I used the boat for commercial fishing I would call it fishing boat. But since I use it for non-commercial fishing, aka sport fishing, a form of play, I call it a sport-fishing boat.
To help you with the concept of catching fish for fun, aka sport, I have attached the following photos. While I realize the creatures I am holding in each photo appear quite different from each other, I can assure you that both of them are, indeed, fish. (If you want more than just my word for this I can refer you to some ichthyology reference books.)
I was not paid to catch either one of these fish, nor did I sell them. Nor do I have a commercial BC fishing license. Therefore, I was not fishing commercially, I was fishing for SPORT (see the definition above).
Oh, one more thing since I know you'll call me on it at some point. I refer to my boat as an OUTBOARD sportfishing boat, right? Here's why.
OUTBOARD MOTOR per Webster's Dictionary: A small, internal combustion engine with propeller integrally attached for mounting at the stern of a small boat. (This definition is a bit vague because "small" is open to interpretation. I would not consider a 300 hp Yamaha to be a "small" engine, nor would I consider a nearly-30-foot Grady White to be a "small boat.")
But regardless of the "small" business, our boat is an OUTBOARD boat because there are two of them mounted on the transom.
I hope I have cleared up your confusion, at least to a degree.