- 2 days with identical surf height can have different energy depending on the underlying swells
- Other factors (e.g. the depth of the water and gradient of the beach, the tide, and the sandbars/reef) will affect how powerful the surf feels
- 300kJ could be really powerful at one beach but less so at another, due to how the waves approach that spot and the effect of differences in the ocean floor.
- For anyone making home-calculations, be sure to use metric units!
Why use this new metric?
It is useful to have a single unit that brings together height and period.
Wave size is still a good indicator to know your limits. However, as the largest contributor to energy is wave height, you might want to start taking note of energy, too.
If 4-5ft is your limit because you've had good days and bad days at that size, the energy might tell you the crucial difference!
Get a headstart on understanding this metric - energy is showing on our historical forecasts! Find some memorable days (for better or for worse) and create a mental record of your threshold.