My main feedback for lagoons is that they are hard to see them from overhead or from viewing galleries because of how murky the water is. If possible, make the water less murky and more clear so it will be easier to see them. This could be why there are no decorations for the lagoons right now- it’s too hard to see kelp or rocks.
The shark feeder could be useable by other large marine carnivores, so it has more use besides the mosasaur.
Ideas:
Landscaping brushes or placeable items in lagoons. Kelp forests, corals, smaller schools of fish and rocks that they swim around are all ideas to make it look more natural.
Larger viewing galleries- the current ones are nice but being able to make wider and bigger ones will improve out view when we look out of them- plus the current sized ones seem small compared to how big lagoons can get.
Floating islands:
You are able to place a piece of land in a lagoon that can be terraformed and have rocks/ trees added to it. You can connect it to a bridge that goes over the lagoon or choose not to. The largest size can have a hotel or guest amenity buildings on it. So you can use them for decoration or for guests. Maybe even having a land animal paddock on it. The size of the island will reduce the total lagoon size so you may need to make the lagoon bigger to accommodate the animals living in them.
Tour tunnels and underwater domes:
Being able to see our lagoons from below might be even better in terms of lighting and seeing the dynamic animations. For tunnels there can be two kinds:
Pedestrian tunnels- where it goes from one side to another allowing access to different parts of the park. Foot traffic only. From either side of the tunnel guests have a view of the lagoon.
Vehicle/ Monorail tunnels- Where tour vehicles and the monorail can cruise through a tunnel to give a great view of the animals. Vehicles/ monorail only. From either side of the tunnel guests have a view of the lagoon.
My favorite- a underwater dome. A dome needs one connection to a path/vehicles tunnel and it can be in different sizes. The largest size domes could have amenities, decorations and small hotels inside- how cool would it be to eat lunch underwater or look out your hotel window to see marine animals? Domes, like tunnels, are on the bottom of the lagoons. A large dome will take swimming space away from a lagoon so it will have to be built even bigger to accommodate the animals. You can connect a foot traffic and a vehicles tunnel to it.
**EDIT I changed "Bubbles" to "underwater domes" as that makes much more sense. Lack of coffee in the morning