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How to avoid this and have a good run-up over the Island
Your model is actually crashing. You can make the model more stable by either reducing the timestep value (dt) or increasing the epsilon variable in the CML file. Note that, while using larger epsilons makes the model more stable, it introduces artificial resistance and decreases the runup.
Increasing the friction coefficient will also make your model more stable.
Thank you :) Will try and let you guys know.