is a 2.5L OMC inboard I see nothing on port side.
Ayuh,.... Welcome Aboard,..... Look closer,..... The starboard side of the block is the oil side,...
Down low on the port side, 'bout mid-block, just above the oil pan is the drain port for that motor,...
The manifold drain is just above the block drain, on the bottom side of the manifold, upside-down,....
Also, if ya got P/S, there's the P/S cooler in the hose comin' from the drive,....
'n ya oughta pull the Big hose off the circulatin' water pump, as it can hide 'bout another quart of water,....