Really love the whale! But I'm not the biggest fan of the layouts of the coasters. Also are you going to add themes? If so then while laying out the rides and coasters make sure you also consider how you want them to interact with your themes/areas. I think your next step should definitely be putting some focus on actual buildings for themes/restaurants/toilets etc.
Nice Park and Coaster! [up]
I should try and flatten the tail of the whale if you can, as it looks a little too fat. The head of the whale with the open mouth where the coaster goes through looks good.