South Africa

Best Time to Dive in the Aliwal Shoal

30.27°S 30.83°E

Conditions are good all year, so the month is decided by wildlife: June to November for sand tiger shark.

Best time
Any month
Water
22–26 °C
Visibility
10–30 m
Dived from
day boat
Tidal range
0.6–1.8 m
Species logged
19

Worth knowing: 96% of days see seas over 1.5 m.

Where it is

South Africa
50 kmN

222 km across · coastline from Natural Earth 10m

Diving in the Aliwal Shoal — monthly breakdown

Conditions do not vary here

Conditions barely change across the year, so no month beats another — pick on wildlife or price.

A year of scuba diving conditions at a glance. Hover a month to isolate it.

Month by month conditions, water temperature, visibility and marine life
JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
ConditionsPoorPoorPoorPoorPoorExcellentExcellentExcellentExcellentExcellentExcellentPoor
Water temp (°C)262626252423222222222325
Visibility (m)15–2520–3015–2515–2515–2510–2010–2010–2010–2010–2015–2515–25
Marine lifeSteadySteadySteadySteadySteadyBusyBusyBusyBusyBusyBusySteady
Excellent Good Moderate PoorSame all year

Long-term averages, 2016–2025. Visibility is estimated from satellite chlorophyll-a. Water temperature is the surface mean; it is cooler at depth.

The Aliwal Shoal diving season

2 seasons

June to November · Peak season

6 months
Water temperature
22–23 °C
Visibility
10–20 m
Rain
8 days a month

Diving conditionsThe wind is up. It rains less.

Marine lifeSardine (hit-or-miss), Sand tiger shark (likely) peak at Aliwal Shoal in these months.

December to May · Off season

6 months
Water temperature
24–26 °C
Visibility
15–25 m
Rain
10 days a month

Diving conditionsIt rains more.

Marine lifeTiger shark (hit-or-miss), Sailfish (hit-or-miss), Striped marlin (hit-or-miss), Scalloped hammerhead (hit-or-miss) peak at Aliwal Shoal in these months.

  • Spring tides run 1.8 m against 0.6 m on neaps, so currents build around the full and new moon.
  • Water temperature is satellite sea-surface temperature, so expect it cooler below the thermocline.
  • Visibility is estimated from satellite chlorophyll-a.

Aliwal Shoal water temperature and weather

2,269 underwater observation records · 31 surveyed years of ocean data · 10 years of sea temperature

Water & weather

Aliwal Shoal water temperature by month

The dashed line is the monthly average. Eight days in ten fall inside the band.

2022242628JanFebMarAprMayJunJulAugSepOctNovDecSea temperature (°C)

10th to 90th percentile rangemonthly mean

29
rough days a month

Seas top 1.5 m on 95% of days. Enough to cancel a day boat

1
blowy days a month

Gusts over 40 km/h, about where a day boat stays in port

9
wet days a month

2 of them bring heavy rain

Monthly sea state, wind, rain, air temperature and daylight
MonthSwellGusts over 40 km/hWet daysHeavy rainAirDaylight
January2.6 m1%11328 °C13.8 h
February2.8 m2%12428 °C13.1 h
March3.0 m0%10327 °C12.2 h
April3.1 m1%9225 °C11.3 h
May3.2 m0%5124 °C10.5 h
June3.5 m1%3123 °C10.1 h
July3.3 m3%4123 °C10.2 h
August3.9 m4%6123 °C10.9 h
September3.7 m3%10223 °C11.8 h
October3.5 m5%12324 °C12.8 h
November2.9 m2%12325 °C13.6 h
December2.8 m2%13326 °C13.9 h

Swell is the rough end of the month: nine days in ten come in under it. Sea temperature covers 10 years, waves 4.

Pick your week

48 weeks from the daily record. Darker is better, against this site's own year. Pick a month for the detail.

Conditions by week, four weeks per month
Week 1January week 1: PoorFebruary week 1: PoorMarch week 1: PoorApril week 1: ModerateMay week 1: PoorJune week 1: ExcellentJuly week 1: GoodAugust week 1: GoodSeptember week 1: GoodOctober week 1: ExcellentNovember week 1: ExcellentDecember week 1: Poor
Week 2January week 2: PoorFebruary week 2: PoorMarch week 2: PoorApril week 2: ModerateMay week 2: PoorJune week 2: GoodJuly week 2: GoodAugust week 2: ExcellentSeptember week 2: GoodOctober week 2: ExcellentNovember week 2: ExcellentDecember week 2: Moderate
Week 3January week 3: PoorFebruary week 3: ModerateMarch week 3: ModerateApril week 3: PoorMay week 3: ModerateJune week 3: GoodJuly week 3: GoodAugust week 3: ExcellentSeptember week 3: ExcellentOctober week 3: ExcellentNovember week 3: GoodDecember week 3: Poor
Week 4January week 4: PoorFebruary week 4: ModerateMarch week 4: PoorApril week 4: PoorMay week 4: PoorJune week 4: GoodJuly week 4: ExcellentAugust week 4: ExcellentSeptember week 4: ExcellentOctober week 4: ExcellentNovember week 4: GoodDecember week 4: Poor
Excellent Good Moderate PoorBest week to go: first of June

June, week by week

WeekConditionsWaterSwellWindRain chance
Week 1Excellent23 °C3.7 m20 km/h15%
Week 2Good23 °C3.7 m20 km/h13%
Week 3Good23 °C3.5 m20 km/h9%
Week 4Good23 °C3.2 m20 km/h7%

10 years of daily records, averaged into weeks.

Gear & storms

What to wear

Off the coldest water of each month, not the average — that is what the suit has to cope with.

Wetsuit thickness by month
JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
SuitJanuary: 3 mmFebruary: 3 mmMarch: 3 mmApril: 3 mmMay: 5 mmJune: 5 mmJuly: 5 mmAugust: 5 mm +September: 5 mmOctober: 5 mmNovember: 5 mmDecember: 5 mm
  • Jan–Apr3 mm full suit
  • May–Jul5 mm full suit
  • Aug5 mm with hood and gloves
  • Sep–Dec5 mm full suit

Swell through the year

The rough end of each month — nine days in ten come in under it.

JanJanuary: 2.6 metresFebFebruary: 2.8 metresMarMarch: 3.0 metresAprApril: 3.1 metresMayMay: 3.2 metresJunJune: 3.5 metresJulJuly: 3.3 metresAugAugust: 3.9 metresSepSeptember: 3.7 metresOctOctober: 3.5 metresNovNovember: 2.9 metresDecDecember: 2.8 metres

Amber is over 1.5 m.

Tides

springs 2.1 mneaps 0.4 mneapsone lunar month
Daily tidal range across one lunar month.

Tropical storms

1 of the last 30 Aprils saw a tropical storm pass within 250 km. April is the only month with a recorded pass.

JanJanuary: 0 of 30 yearsFebFebruary: 0 of 30 yearsMarMarch: 0 of 30 yearsAprApril: 1 of 30 yearsMayMay: 0 of 30 yearsJunJune: 0 of 30 yearsJulJuly: 0 of 30 yearsAugAugust: 0 of 30 yearsSepSeptember: 0 of 30 yearsOctOctober: 0 of 30 yearsNovNovember: 0 of 30 yearsDecDecember: 0 of 30 years

Share of the last 30 years with a storm that month.

  • NOAASea surface temperature, from OISST and MUR
  • ERA5Wind, waves, rain and air temperature, via Open-Meteo
  • OBISMarine species records within 60 km
  • IBTrACSTropical cyclone tracks, 1996 to 2025

Aliwal Shoal marine life — what you'll see diving

2,269 records within 60 km
SpeciesWhenObserved windowReliabilityEvidenceRecords
Humpback whaleJun–AugLikely
14/31
59
Yellowfin tunaAll yearLikely
13/31
1451
Potato codAll yearLikely
12/31
41
Tiger sharkMarHit-or-miss
9/31
34
SailfishJan–MarHit-or-miss
9/31
58
Hawksbill turtleAll yearHit-or-miss
9/31
37
Bull sharkFeb–MarHit-or-miss
8/31
174
Striped marlinDec–JanHit-or-miss
6/31
63
Scalloped hammerheadMarHit-or-miss
4/31
22
Smooth hammerheadMarHit-or-miss
2/31
25
Spotted eagle rayMarHit-or-miss
3/31
22
Green turtleAll yearHit-or-miss
6/31
17
Whale sharkJan–MarHit-or-miss
4/31
17
Oceanic mantaMarHit-or-miss
2/31
20
SardineJunHit-or-miss
5/31
11
Sand tiger sharkMar, Jun–Jul, NovLikely
13/31
138
Common thresherMarHit-or-miss
2/31
8
Loggerhead turtleDec–Jan, AprHit-or-miss
5/31
18
Ocellated eagle rayFeb, NovHit-or-miss
5/31
8
Peak Present
Observed window
Months with records. Peak is where most of them fall.
Reliability
  • Near-guaranteed in 60% of surveyed years or more
  • Likely 30% to 60%
  • Hit-or-miss under 30%
Evidence
Years it was seen, out of the years anyone surveyed.
Records
OBIS sightings within 60 km.

These are sightings people logged, not a full survey of the reef. A species missing from a month may just mean nobody recorded one.

Diving the Aliwal Shoal — common questions

When is the best time to dive the Aliwal Shoal?
Conditions barely change across the year at Aliwal Shoal, so any month works — pick on wildlife or price.
When is the diving season at the Aliwal Shoal?
There is no real season at the Aliwal Shoal: conditions barely change, so you can dive any month.
Is the diving at the Aliwal Shoal good for beginners?
It is better with some experience. It suits Advanced Open Water divers or equivalent, so newer divers should ask the local operator which sites fit their level.
How warm is the water at the Aliwal Shoal?
Between 22 and 26 °C at the surface across the year, coldest in August and warmest in February. It runs cooler below the thermocline.
What wetsuit do I need at the Aliwal Shoal?
A 5 mm with hood and gloves covers the coldest water of the year. In the warmest months a 3 mm full suit is enough.
What is the visibility like at the Aliwal Shoal?
Roughly 10 to 30 m depending on the month. That is estimated from satellite chlorophyll-a rather than measured in the water.
What will I see diving the Aliwal Shoal?
The most consistently recorded species are Humpback whale (likely), Yellowfin tuna (likely) and Potato cod (likely), from 2,269 records within 60 km.
Does the Aliwal Shoal get tropical storms?
Yes. Over 30 years of records a storm passed within 250 km in Apr, most often in April at 1 of 30 years.
Is there current at the Aliwal Shoal?
The tide rises and falls 1.8 m around the full and new moon, against 0.6 m in between. How much of that becomes current depends on the shape of the channel.
How do you dive the Aliwal Shoal?
Mostly from day boats. Trips run through the season, Dec–Jul.