Water Intake Issue

2004 Malibu VLX

My boat is not sucking water from the lake - therefore it is overheating. I have a clear flush kit installed on the intake hose and I can clearly see that water is not coming into the engine.
Leading up to this - I noticed a bad leak at the impeller. Further research showed two bolts were missing from the face plate. I went to the dealer - he gave me the two bolts and a new gasket for mounting. I installed the new gasket and bolts and went to the lake all day saturday without issue. I dont think its related, but maybe. Sunday it began to overheat 100 yds from the boat ramp.

What are some simple checks? The impeller only has roughly 100 hrs on it. The grate and thru hull hole are clear. Back yard mechanic question, but is there a water pump or does the impeller work in lieu of a pump?