Press R for the rod. Hold the left mouse button to wind up, release to cast: the longer you hold, the farther it goes.
Watch the bobber. A few nibbles, then it's pulled under: click the left mouse button that moment to set the hook.
In a fight, hold to reel but keep the line tension in the green. Ease off when the fish runs, or the line snaps.
What bites depends on where you fish: the shallows, the reef, the deep water past the drop-off, and the time of day.
Joe at the fish stand by the pier buys your catch. Fish are worth more by weight, so bring the big ones in.
Marta at the boathouse sells upgrades: stronger line, a faster reel, a bigger hold, more fuel and a fish finder.
Press E at the boat to board, at the wheel to take the helm, and again to step away and walk the deck.
Press I for your cooler and the fish log. Deck lights from Marta let you fish after dark.
Got a headset? Settings → Camera → Virtual reality → Enter VR. Without one, the same button shows stereo side by side.