Submarius
Spearfishing conditions in Big Island (Hawaii)
Kona side drops off faster than almost anywhere in the world: 1000ft contour within a mile of shore. Big blue marlin and yellowfin tuna within sight of the harbor.
Before you get in the water, open the app for the swell, wind, tide, water temperature, current and a visibility estimate for Big Island, HI.
Notable species
Big Island (Hawaii) is known for:
Typical water visibility
Summer visibility around Big Island (Hawaii) is commonly reported in the 50 to 120 ft range, a community guidance estimate, not a measurement. Rain, river discharge, swell mixing, and seasonality can shift real conditions dramatically day to day.
The app shows a model estimate of today's visibility here, with a confidence figure.
How the visibility estimate works →Last 7 days of model reads
One model estimate recorded each morning (UTC) for Big Island (Hawaii). These are model estimates, not measurements; the low and high columns are the p10 to p90 range around the middle estimate.
| Day | Low ft | Estimate ft | High ft |
|---|---|---|---|
| Oct 15 | 44 | 68 | 98 |
| Oct 14 | 44 | 68 | 98 |
| Oct 13 | 44 | 67 | 98 |
| Oct 12 | 43 | 66 | 97 |
| Oct 11 | 43 | 65 | 96 |
| Oct 10 | 43 | 64 | 94 |
| Oct 9 | 43 | 64 | 94 |
Table baked Oct 15, 2026; days the recorder missed are simply absent.
Clearest months at Big Island (Hawaii)
Model climatology from the baked clarity ceiling: the typical day and the best case (90th percentile) visibility for each month, with a seasonal algae bloom proneness flag. These are labelled model estimates, not measurements.
| Month | Typical ft | Best case ft | Bloom risk |
|---|---|---|---|
| Jan | 59 | 72 | low |
| Feb | 59 | 98 | low |
| Mar | 59 | 79 | low |
| Apr | 59 | 92 | low |
| May | 80 | 115 | low |
| Jun | 82 | 98 | low |
| Jul | 79 | 98 | low |
| Aug | 72 | 98 | low |
| Sep | 66 | 98 | low |
| Oct | 66 | 98 | low |
| Nov | 72 | 98 | low |
| Dec | 62 | 98 | low |
Ceiling artifact global-reef-v10-obis-world; table baked Oct 15, 2026.
What Submarius shows for Big Island (Hawaii)
This page reads Big Island (Hawaii) at 19.54°N, 155.67°W, in Hawaii. Open the same point in the app for:
- A 0 to 10 rating. For spearfishing at Big Island (Hawaii) today, from Rough to Prime, and you can tap any factor to see why.
- Best 3 hour window. The three hours in the next 24 that score best.
- Tide. Rising, falling or slack, the next high or low, and a 24 hour curve.
- Wind. Speed and direction, with gusts.
- Waves and swell. Wave height and swell, with the second and third swell by the hour.
- Water temperature. With the air temperature underneath.
- Current. Drift in knots and the next slack, from a regional model, so it's offshore drift, not your entry.
- Visibility estimate. A model estimate with a confidence figure, not a measurement.
- Weather warnings. National Weather Service warnings for this spot and its marine zone.
- 8 day forecast (Pro). Days 2 to 8, hour by hour.
Big Island (Hawaii) spearfishing map: reefs and wrecks
The reefs and wrecks layer in the app marks charted wrecks, reefs and obstructions around Big Island (Hawaii), where sources have them. Tap one for the seabed depth beside it (an estimate where no chart reports one), the least depth over the structure where a chart sounding exists, and today's conditions at that spot. The structures are merged from NOAA nautical charts and other public sources, so coverage is densest in US waters. It's a Pro map layer.
See the spearfishing map →Safety in the water
Every safety tool in Submarius is free. With Safety Watch you set a "back by" time and pick who watches. If you don't check in by then, the server alerts them by push or email, even if your phone is dead. It needs a free account and never contacts the coast guard.
In Spearfishing mode, a shark awareness card lists shark species recorded around Big Island (Hawaii) (from OBIS records, for awareness, not live tracking) and community sightings from the last 48 hours, when the area has any. Signed in users can report a sighting, and app users within 25 km get a push.
Also at Big Island (Hawaii)
More spearfishing locations
See all →Check Big Island (Hawaii) before you head out
Today's conditions, safety tools and trip recording are free. Pro adds the 8 day forecast, the Pro map layers, cam playback and offline areas for $12.99 a month or $99 a year, or $149 once (US prices).