I am not saying HGVC Sea World is FAR from Sea World... I said it was about 2 1/2 blocks... not miles.
And while the hotel is close to the entrance for the parking lot to Sea World, it is not 'right there' which might be worth noting. I have hip issues (and a 4 yo DD) and cannot walk for excessive distances and everyone assured me we could 'easily walk' to Sea World. That was definitely not the case -- we could walk to the edge of the parking area but it's a hike across the lot to the entrance of the park. I was just trying to help OP because if he has young kids, it's good to know what to expect.
The splash park is a gated area next to the pool that has a bunch of fountains that spurt up in random intervals and totally enthralled my DD until I had to drag her away. Neither of the pools had a water slide, but there is a fountain in the middle of one and a large waterfall in the second. The kids seemed to LOVE the waterfall -- swimming under it, through it, around it.
There is also a kids pool, but it's very small and limited, however the shallow portions of both pools was right around 3 feet and I think the deepest was 5' (I might be wrong on the waterfall pool). There are also three hot tubs scattered among the pools, and while they aren't for kids, it's a great thing for adults after hoofing it around the park.