MYSTERIOUS HOTEL DELFINO
Sirena 3 incorporates a very valuable trick to skip the entirety of the level. Usually you would have to search through the whole hotel for a pineapple for Yoshi and go through the vents to the shine, but with this clip you can go straight there. This is a level that is a lot easier than it may seem.
Sirena Entry Movement
As every level in Sirena Beach involves talking to the Hotel Manager, they all have the same beginning movement. The most efficient is to do a dive rollout in the Up Right direction, and to do a single jump, while spraying, towards the stairs and dive into the water. It can be tricky at first, but only changes based on the length of the rollout
Grabbing the Banana
The most optimal movement for grabbing the banana is doing a jumpdive rollout on the floor seperating the two pools and to rollout into a grab. To do this simply roll out of a dive and spam B. If this fails, single jump next to the banana and spam B to to do a dive and grab it.
To get the easiest railing kick setup, do a double jump and kick off the pole at the center of the lobby at the apex of the jump. Once near the pool with the shine in it, turn so that Mario is facing toward the middle of the hotel and do a backflip (hold R and press A). Make sure that when positioning yourself that the apex of this backflip will happen as Mario hits the wall. When he does, flick forward on the stick and throw the fruit. The timing and execution is a lot more lax on this trick than it may seem.