No it is not the same gravity. Inertia causes the tides in the oceans ans seas but is diminished or is absent in seas and lakes.
What causes this inertia is another question.
I will continue with happenby's post.
YES it is the same gravity. It took me a few seconds to google "what causes the oceans tides" to get the official science answer that it is gravity.
The point is clear, that gravity for modern science is the cause of the oceans tides. Perhaps not to geo-centrists like you, but nobody cares about geocentrists anymore. No one ever did really.