I had to actually look up what you those two items entailed. Looking at the description and seeing that it's basically freediving while being towed by a jetski I feel confused about you saying you're a beginner.
If you're really a beginner snorkeler / freediver, I would really, REALLY, advise you not to get started with stuff like that. If you're just a beginner to this specific niche, you'd probably be better off contacting a specific community that engages in this sport.
Given that this seems to be an extreme niche thing however, I expect that both of these devices will need to have their fair share of development time in the future.