Perhaps this is the first time you may see a double ocean monument in Minecraft. Among two of them, one monument looks different with some destroyed parts. The reason is that another monument cuts off the rest one. You must download the higher 0.15.9 version to enable this seed.
Your first responsibility should be drinking a potion of night vision, which helps you live in the creative mode. One fact is that the survival mode is more challengeable than the creative one.
An island with the medium size is the place for you to spawn. Look at the following picture. At your position, you need to fly ahead.
Then, you will see the general overview of two ocean monuments after a short time of flying.
It takes you a short time to get to the monument. A noticeable feature is the destroyed part of the monument.