The three upgrades
Line Strength raises how much weight your line can hold before tension hits 100%. Dive Depth extends the winch cable so you can turn around deeper, where the valuable species live. Spotlight Power widens and brightens the beam so you can see hazards and fish sooner in dark water.
Full cost table
| Level | Line Strength | Dive Depth | Spotlight Power |
|---|---|---|---|
| Start | capacity 100 | 95 m | radius 150 |
| 1 | 125 · 40 coins | 165 m · 50 | 185 · 30 |
| 2 | 155 · 90 | 265 m · 110 | 220 · 70 |
| 3 | 190 · 180 | 385 m · 220 | 260 · 140 |
| 4 | 230 · 340 | 525 m · 420 | 300 · 260 |
| 5 | 280 · 600 | 685 m · 760 | 345 · 480 |
| 6 (max) | 340 · 1000 | 820 m · 1300 | 400 · 800 |
| Total | 2,250 | 2,860 | 1,780 |
Maxing everything costs 6,890 coins.
Why depth comes first
Coin income depends almost entirely on which species you can reach. At the starting 95 m limit you meet sardines, glowfins and mackerel, worth 3–9 coins each. One Dive Depth upgrade (165 m) opens the twilight zone with lanternfish (14) and barracuda (24). The next ones unlock hatchetfish, anglers and viperfish, and at 385 m the first Giant Squid (160) can appear. Each depth level multiplies what a good ascent is worth.
Our recommended order
- Depth 1 (50) — twilight zone.
- Line 1 (40) — room for a few barracuda.
- Depth 2 (110) — hatchetfish and the first anglers.
- Spotlight 1–2 (30 + 70) — below about 200 m the water gets dark enough that the beam starts to matter.
- Line 2–3 (90 + 180) — anglers weigh 15; you need the capacity.
- Depth 3 (220) — 385 m, Giant Squid and viperfish.
- Line 4 (340) — so one squid is 11% instead of 25%.
- Depth 4 (420) — 525 m, Gulper Eels and the Leviathan Ray.
- Spotlight 3–4 — the abyss is nearly black; wider light means fewer surprise jellyfish.
- Depth 5 (760) — 685 m, the Ghost Shark zone. Worth 320 coins each.
- Finish Line, Spotlight and Depth in whatever order fits your play style.
Signs you bought the wrong thing
- You keep snapping lines → your depth has outgrown your line. Buy Line Strength before the next depth level.
- You keep losing hull on the way down → you can't see hazards in time. One or two Spotlight levels help more than you'd expect.
- Your ascents feel empty → you are over-investing in line and light. Go deeper.
Is grinding worth it?
You never need to grind. A single good ascent at 525 m with one Leviathan Ray and a couple of anglers pays for the next depth level. Focus on landing catches rather than maximising every dive — a snapped line is the most expensive mistake in the game.