Diving and snorkeling in Cidade Nova
Today, Wednesday, October 28, 2026 · local time (GMT-3) · Río de Janeiro, Brazil Today, Wed, Oct 28 · GMT-3- Slack water
- 3:30–4:03 am, 10:30–11:10 am, 3:24–3:54 pm and 10:10–11:20 pm
- Swell
- 2.6 ft, 7 s
- Water and suit
- 74.3 °F · 3 mm wetsuit
- Likely visibility
- Fair
Today, Wednesday, October 28, the best time to dive in Cidade Nova is 9:30 am to 11:40 am, with slack water at low tide, light wind, weak current and the sun high. It's a good day (8/10). Visibility is likely fair. Water at 74.3 °F: a 3 mm wetsuit. The best day this week is Tuesday, November 3, at 9/10.
Your diving day in Cidade Nova at a glance
The strip runs from midnight to midnight, local time. Daylight on top; then the tide with its slack water (purple bands), the conditions hour by hour and the best times.
Today in detail
Likely visibility: fair- Slack water today: high tide 3:48 am (3:30–4:03 am), low tide 10:52 am (10:30–11:10 am), high tide 3:39 pm (3:24–3:54 pm) and low tide 10:57 pm (10:10–11:20 pm)
- Likely visibility: fair. Swell (up to 4.9 ft at 9 s) over the last few days has stirred up the water. Based on the last 24 hours of data.
- Water at 74.3 °F: a 3 mm wetsuit.
- Snorkeling: doable, with some waves or wind.
- Night dive: dark from 6:27 pm. Waning gibbous (92%), rising at 9:03 pm: a bright night.
Slack water comes from the tide: in inlets, channels and between islands the water can keep running for an hour or two after. Ask the local dive shop.
Never dive alone and check with the local dive shop: this rating is a guide, not a substitute for a professional.
Diving forecast for the next 7 days
| Day | Rating | Best times | Swell | Visibility | Water |
|---|---|---|---|---|---|
| Today | 8 good day | 9:30–11:40 am3:10–4:10 pm | 2.6 ft · 7 s | Fair | 74.3 °F · 3 mm wetsuit |
| Thu 29 | 9 great day | 9:40 am–12:40 pm3:40–4:40 pm | 1.4 ft · 7 s | Fair | 74.1 °F · 3 mm wetsuit |
| Fri 30 | 9 great day | 7:50–10:50 am5:10–6:00 am | 1.4 ft · 6 s | Fair | 73.9 °F · 3 mm wetsuit |
| Sat 31 | 9 great day | 8:40–11:40 am4:50–6:00 pm | 1.4 ft · 9 s | Fair | 74.7 °F · 3 mm wetsuit |
| Sun 1 | 9 great day | 8:40–11:40 am2:50–4:00 pm | 1.5 ft · 5 s | Fair | 75.2 °F · 3 mm wetsuit |
| Mon 2 | 8 good day | 10:00 am–1:00 pm3:50–5:20 pm | 2.0 ft · 5 s | Fair | 76.1 °F · 3 mm wetsuit |
| Tue 3 | 9 great day | 10:30 am–1:30 pm4:40–6:00 pm | 2.0 ft · 6 s | Good | 76.3 °F · 3 mm wetsuit |
Each day's rating comes from the swell, waves, wind, current, slack water, daylight and likely visibility. The forecast reaches about 7 days.
Dive sites, wrecks and dive shops nearby
Map: OpenFreeMap · © OpenMapTiles · © OpenStreetMap contributors
- Wilhelmina 2.6 mi
- Cori Brothers 4.0 mi
- Magdalena (fore Section) 5.8 mi
- Wreck 3.2 mi
- Área de Proteção Ambiental do Morro do Leme, Urubu e Ilha de Cotunduba 4.5 mi
- Monumento Natural do Arquipélago das Ilhas Cagarras 9.4 mi
- Mar do Rio 2.0 mi
- Coral de Fogo Diving Experience SSI 2.9 mi
- Tiburón Dive Shop 4.1 mi
- XDivers Scuba School 5.2 mi
- Diving Club - Escola de Mergulho 5.7 mi
- TECNOSUB Mergulho Profissional 6.1 mi
Within 12 mi. Some may be missing or closed; marine reserves usually need a permit. Open the map on OpenStreetMap · Missing one? Add it to OpenStreetMap
Wreck and reef positions are approximate and not for navigation; a wreck’s depth runs from the top of the hull to the seabed.
Sites: © OpenStreetMap contributors (ODbL). Wrecks: EMODnet Human Activities (AND-International), from UK Hydrographic Office data, CC BY 4.0. Contains public sector information licensed under the Open Government Licence v3.0.
How we work out the diving rating
We score every moment of the day, every 10 minutes, from 0 to 10, with simple fixed rules:
- Swell: takes points away based on its height and period (a 10 s swell weighs 50% more than a 6 s one, because it reaches deeper and moves the bottom): nothing under 1.6 ft, up to 6.5 points from 9.8 ft. Surface waves count for getting in and out; we take the worse of the two.
- Wind: takes points away from force 4, about 12 mph (1 point), up to 6 points in a gale; half a point more when it blows offshore, because it pushes surface swimmers away from shore.
- Current: Météo-France's model current takes points away from half a knot (1 point) up to 6 points from 2 knots.
- Slack water: where we show the tide, up to 3 points come off when the water rises or falls fast (mid-tide, especially on spring tides) and none at slack, around each high and low tide.
- Light: half a point more with the sun high (3 hours either side of solar noon), 1.5 less at twilight and 3 less at night. Thunderstorms take away 5 and heavy rain 1.
- Likely visibility: good, fair or poor from the swell of the previous 48 hours, the rain of the previous 72 and the wind of the previous 24. Fair takes 1 point off the day's rating and poor, 2.
- Day's rating: the average of the best window (the stretch of 40 minutes to 3 hours with the best conditions), adjusted for likely visibility.
- Wetsuit, by water temperature: below 50 °F, drysuit; from 50 °F, 7 mm semi-dry; from 57 °F, 7 mm wetsuit; from 64 °F, 5 mm; from 72 °F, 3 mm; from 79 °F, shorty or rash guard.
Today: the best window scores 9.2 out of 10 and visibility is likely fair, so it takes 1 off.
It's an estimate from the swell, rain and wind of the previous days, not a measurement: real visibility also depends on the bottom, plankton and nearby rivers.
Slack water comes from the tide: in inlets, channels and between islands the water can keep running for an hour or two after. Ask the local dive shop.
It is a guide built from models, not a guarantee: every site has its own currents and bottom. Look at the water when you get there and ask the dive shop.
Before you get in the water
- Never dive alone: always with a buddy and, if you don't know the site, with a dive shop.
- Check with the local dive shop or club: they know the currents, the no-dive zones and how the water is today.
- Dive within your certification and experience, and stay within depth and no-decompression limits.
- Fly a dive flag (diver-down or alpha flag) on a float and watch for boat traffic.
- Marine reserves need a permit and often have quotas: ask before you go.
- This rating doesn't replace a professional's judgment or what you see when you arrive: if the sea doesn't look right, don't go in.
Questions about diving in Cidade Nova
Can you dive in Cidade Nova today?
Today is a good day (8/10). The best time is 9:30 am to 11:40 am, with slack water at low tide, light wind, weak current and the sun high.
What about tomorrow? When's the best time to dive in Cidade Nova?
Tomorrow, Thursday, October 29: 9:40 am to 12:40 pm, with a rating of 9/10.
Which day this week is best for diving in Cidade Nova?
Tuesday, November 3, at 9/10. Its best time is 10:30 am to 1:30 pm.
When is slack water in Cidade Nova today?
Today the water barely runs at these times: high tide 3:48 am (3:30–4:03 am), low tide 10:52 am (10:30–11:10 am), high tide 3:39 pm (3:24–3:54 pm) and low tide 10:57 pm (10:10–11:20 pm). It's an estimate from the tide: in inlets and channels slack water can come later. Ask the local dive shop.
What will the visibility be like in Cidade Nova?
Likely fair. Swell (up to 4.9 ft at 9 s) over the last few days has stirred up the water. Based on the last 24 hours of data. It's an estimate, not a measurement.
What wetsuit do I need to dive in Cidade Nova?
Water at 74.3 °F: a 3 mm wetsuit. If you get cold easily or plan several dives, go thicker.
Can you dive at night?
Yes, with experience, a primary and a backup light, and ideally with a dive shop. Night dive: dark from 6:27 pm. Waning gibbous (92%), rising at 9:03 pm: a bright night.
How is the rating worked out?
From the swell and its period, the waves, the wind, the current, slack water, daylight and likely visibility. Each factor adds or takes away a fixed number of points and the rating sums up the best window of the day out of 10.
More about Cidade Nova today
Learn more
Our own calculation: tide from Ilha Fiscal (Rio de Janeiro, TICON-4), sun and moon with astronomy-engine, and sea and weather from Open-Meteo (Météo-France, ECMWF, NOAA GFS and Copernicus Marine, CC BY 4.0). Dive sites: © OpenStreetMap contributors (ODbL). Slackwater database (https://github.com/openwatersio/slackwater-database). Source: Hart-Davis, M., Dettmering, D., Seitz, F. (2025), TICON-4: TIdal CONstants based on GESLA-4 sea-level records, SEANOE, https://doi.org/10.17882/109129. Licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Modified: see https://github.com/openwatersio/slackwater-database#modifications-to-source-data