If you're looking to get your hands on a seahorse in Dave the Diver, you've likely realised that finding them isn't the problem. You'll see them all over the ocean when you're exploring the reefs to restock your sushi restaurant, but no matter what you try, there doesn't seem to be any way to catch these small sea creatures.
Some fish, such as tuna, need specific equipment or weapons to catch them easily, while others might need to be put to sleep in order for you to get close enough to them to deal damage. Likewise, you'll need a specific bit of kit if you want to catch a Dave the Diver seahorse, so here's how to get started.
Dave the Diver seahorse: How to catch one
What you need is a Bug Net, but this useful bit of kit isn't available right away. Instead, you'll need to progress through the story until you get a certain visitor to arrive at the restaurant. Maki is her name and she shows up in chapter 2 when you'll need to serve certain dishes to her. Once you fulfil her dietary requirements, you'll get the Bug Net.
With the Bug Net in hand, head back into the ocean and look for schools of seahorses. They're tiny but often brightly coloured, so they shouldn't be too difficult to spot. You can find them at all depths so, if time—or air—is short, you won't need to dive too far down as they are often found close to the surface around reefs or close to vegetation. Once you've spotted one to catch, position yourself next to it and wait for the space bar prompt to bring the net down and catch it.
The Bug Net isn't used exclusively for catching seahorses either: you can catch other tiny sea creatures too, like shrimp, so it's a tool that keeps on giving—or catching, in this case.