if the top is black…then it really isn’t white.
either will stay the same or will rise
definitely is not going to drop
I’m gonna ask this question to my genuis brother and post the definite answer 
ps: the answer to the conveyor question was a big NO smartasses
Last time we had a question like this I ended up breaking out an RC plane and my treadmill to prove the right answer. Since my pool is frozen solid this one may have to wait until spring.
But you could do the same thing, on a smaller scale, in a bathtub. Instead of a boat use a big rubbermaid container. Put a cinder block in it. Measure the water line. Take the block out, put it in the tub while leaving the rubbermaid container in there as well. Compare the waterline. The physics involved would be indentical so the scale will not matter.
My WAG is the waterline will be higher with the block in the container than with the block in the water. With the block in the water the water will occupy every possible space around the block, where as when it is in the container the container is forced down into the water. Since the container is watertight (aka, a boat) the water gets displaced, and there for goes higher.
But, if the underlying asphalt is white, and comprises of at least 51% of the asphalt, it really isn’t black then, so, wouldn’t it be white-top?
Just my useless opinion, the water level drops because the weight of the rock displaces more water when spread out over the area of the boat. When it is dropped in the water there is less surface area to displace the water. Right or wrong, its just my opinion.
if the water is frozen then the level will stay the same the boat will stay the same and the rock will be sitting on the top he never said it sank. or the rock could go part way into the water being suspended by rope attached to a near by tree…
There are way too many variables for a true scientist to answer the question because scientists do not assume anything.
Edit: So give us the freakin answer damnit!:biglaugh:
I was right.
Tadaaaaa!
Ok Mr Clinton 
Want to debate the meaning of the word “the” next? :lol:
:biglaugh:
damnit, take that out so people can keep fighting
What if the rock was plugging a hole in the boat?
What if the boat is so big that it was actually resting on the sides of the pool, not in the water at all so when you throw the rock in, it adds displacement and the level rises?
What if the boat is a concrete canoe designed by art majors?
What if the boat is really top heavy and when you take the rock out of the bottom the CG shifts so drasticallly that it tips over and sinks?
What if the boat is full of hot naked big tittied bitches?
So yeah, based on intuitive and reasonable assumptions, the water level drops.
I vote for a 3 day ban for the next person who posts a physics problem without all necessary information to mathematically prove the answer and a list of given assumptions.
Q: What if the boat is a concrete canoe designed by art majors?
a concrete boat can still float, just like a stel boat can still float,
Q: What if the boat is full of hot naked big tittied bitches?
then only a physics major would continue to worry about throwing the rock into the pool and checking the water level
i on the other hand would be attemptiong to occupy every vagina on the boat
back on topic, some problems are easiest to visualize if you exagerate the question
picture the rock as being extremely dense … its bb sized and weights 400 pounds
in the boat, its REALY gonna drag the boat down
in the bottom of the pool its hardly going to make a diference in the water level
throw the bb in the water, boat raises, waterline drops, question answered
the same answer will hold true as long as the rock (or cylinder head, or dead body with concrete shoes) that your throwing into the pool is heavier then water … even if its just SLIGHTLY heavier then water
this is why boat size and rock size dont matter, hence why the question didnt realy change when i added to the original post 
so I was right, but had some totally irrelevant parts in my answer?
the water level drops. i was right! yay!
You think that the pool’s water level will lower? That’s absolutely right!
The reason is that, when the rock is in the boat, it displaces its total weight. If it weighs ten pounds, for example, then it’s making the boat ten pounds heavier.
When the rock is sitting at the bottom of the pool, on the other hand, it displaces its volume. As explained in Buoyancy Basics and in the answer to the Buoyancy Question, an object sinks when it weighs more than the water it displaces. To follow the example given above, the ten-pound rock may only displace three pounds of water. (A given volume of rock is typically three to five times heavier than the same volume of water.)
At any rate, the rock displaces more water when it’s in the boat than when it’s in the water, and so the pool’s water level is lower when the rock is in the water.
By the way, this is the question that the physicists J. Robert Oppenheimer and George Gamow answered incorrectly.
DAMN! I voted before thinking… water level will drop, not stay the same…