This manuscript describes a multi-sensor observation of a light-filament in the North Sea. It demonstrates this filament’s life cycle in great detail, combining multiple observational methods. The description of the filament is thorough. The data processing is sound. I recommend the paper’s publication with some minor comments.

Main comments:

1. The authors acknowledge that the tidal flow speed-up and slow-down provide spurious convergence and divergence values. And they can be in constructive or destructive interference with the filament's divergence. I would like this to be more quantitative. How much divergence is due to tidal flow alone? In plots about divergence, a rough value of tidal divergence and its phase is useful to guide the reader to understand when they are in constructive and destructive interference. The estimate for tidal flow could come from the model that the authors used to get the SSH estimate in their data processing.
2. I think we have the opposite understanding of what ``filementogenesis'' is. I take it as processes that sharpen the filament/front, increasing its density/velocity gradient. That means, divergent flow at the light filament center is frontolytic. I can see opinions might differ on the definition because this paper is looking at a light filament, the opposite of the more commonly studied dense filament. The authors can make their own choice here, but should take a paragraph at the beginning of the paper to define the terminology in precise detail.

Minor comments:

1. NSL is not defined anywhere as far as I can see. 
2. Line 27: What makes the anticyclonic strain zone anticyclonic? Strain is defined to be independent of vorticity. In this case, is the vorticity due to the shelf jet? For someone not familiar with the North Sea, some more description would be helpful.
3. Line 28: For the light filament, does the ASC subduct the light anomaly? The classic picture paints it to spread the light anomaly on top with frontal divergence. From what I understood, that's what the observation shows in this paper as well.
4. Line 59: Johnson et al. 2024 is nowhere to be found in the reference list.
5. Line 91: Using km to describe the resolution might be better at such a resolution.
6. Line 375: synoptic usually means O(1000 km), which this paper is not.
7. Line 377: What does "capture the kinetic energy'" means? Fronts usually convert PE to KE.