Hey Tyler, there's nothing wrong with using a board made for the ocean. However, you haven't given us enough info to conclude the likelihood of success with your scenarion. Length, width, thickness of the board, size of the wake and the weights of the various folks riding will have a dramatic effect on your success rate.
Most shortboards will tend to be in the 6'2" x 18.5" x 2.25" range. Also the average surfer, per industry specifications, is in the 150 pound range. If you're 250 pounds trying to ride a 6'2" shortboard for the first time, it might be a struggle.
If you are closer to the averages listed above, or the board is bigger than lited above, you'll have a greater chance for success. Like Chris points out - you need to try wakesurfing, it's great fun.