Type III MSD with macerator pump

[rs2k]

MY boats toilet has a type 3 MSD right under it. Attached to the MSD is a macerator pump that can be operate by a switch elsewhere in the cabin. Since I boat in a lake the system is blocked and no one uses the toilet so I don't have to worry about emptying the MSD. I plan on taking my boat to the ocean this year, since the toilet leads directly to the MSD, do I need to put some kind of valve after the macerator pump? The rules I've found only take about y-valves that lead to the pump or the MSD, I haven't found anything that talks about the setup I have, although I have seen MSD III tanks with pumps built into them like mine before.

Basically, my toilet is setup to be used as a Type III, but I have the option to empty the tank VIA the pump or by sucking it out the top.