AUSTRALIA
Yes, it's reversed Down Under: Australia's winter is during the Northern Hemisphere's summer. That's the easy part. From there, it gets increasingly complex; Australia's diving areas are vast. Although the Great Barrier Reef (or, as our correspondent called it, the Pretty Good Barrier Reef) gets most of the press, better by a hundred miles is the Coral Sea, whose outlying atolls and pinnacles such as Marion Reef offer some of the best diving in the world. Cyclone season is January through March; April, May, and June see heavy trade winds. The best season to dive Australia on a live-aboard (really the only way to see the best) is July through November. Best vis at Osprey, in the northern Coral Sea, is between June and September. The other hot spot for Australian diving is clear across the continent on the remote west coast, and it's famous for one reason: whale sharks congregate at Ningaloo Reef during March and April.

BAHAMAS
May through November is summer in the Bahamas. During these months, the most rain falls and temperatures average about 81°. Winter can bring surprisingly cool weather, with averages down about 70°. Northers can disrupt diving during winter months. The southern islands of the Bahamas chain usually manage to stay a degree or two warmer. Average time between hurricanes is nine years. Easterly trade winds predominate for most of the year, but there is usually a lee to be found for diving.

BELIZE
The dry season runs from March through May. The most predictably good weather for diving is from April through June, when the winds are normally light. Hurricanes hit Belize an average of once every six years. Major hurricanes have hit in 1931, 1961, and 1978. During winter months (mainly December, January, and February), Belize is also subject to northers that blow down and disrupt diving for several days. Water temperature may dip as low as the 70s in the winter and reach as high as 85° in the summer.

BERMUDA
Bermuda is surprisingly far north, located on about the same latitude as Dallas, TX. Winds blow out of the south for most of the summer. In the winter, storms from the west and northwest are common. Water temperature varies from low 60s during the winter to summer highs in the 80s. The average yearly rainfall of 57 inches is generally evenly distributed throughout the year.

CAYMANS
The Caymans' hottest period is from May to November. During winter, temperatures can drop down to the low 70s. Rainy season starts in May and peaks in October. Rains are normally short and intense. Run-off has little effect on Grand Cayman's water clarity, which averages about 135 feet horizontally on the deeper reefs. Both Little Cayman and Cayman Brac boast even higher visibility averages. Water temperatures vary, from the upper 70s in the winter to low 80s during the summer. Trade winds are out of the northeast in the winter and the southeast during the summer. Northwesterly storms can occur from December through April.

EGYPT
Air temperatures in winter range from 60°-75°; thewater can drop down into the upper 60s, with the coolest temperatures occurring in February. Summer land temperatures slide right up past 100°, with the water temperature rising into the low 80s (take a wetsuit anyway). The hottest month is August. If you are going to do any land exploration (and how do you visit the Red Sea without at least a peek at the pyramids), the trade-off for warm water is hot weather. The manta season is from March to June.

FIJI
Fiji's weather presents a real mixed bag. The choice is often between good visibility and cool water or warm water and calmer seas with less visibility. June through October is the dry season when the water is the clearest, but it's also at its coldest and the winds kick up. Water temperatures can sink into the low 70s during this time of the year, making it necessary to drag out the full wetsuits. November brings a transition period. The water warms up, the winds die down, and the plankton blooms, lowering the visibility. By January and February, the water has warmed back up into the low 80s. The rains pick up and the hurricane season is on (December through March). Counting Tonga and Samoa, the area gets about five cyclones a year. It's a risky time to try to catch good diving weather. Because the winds kick up so much in February and March, some resorts pick these months to close down for repairs. During April and May, the wind, and therefore the seas, become calmer and the water remains warm, but the plankton bloom cuts down on the underwater visibility. Of course, this offers the best odds of seeing large plankton eaters. The best time to go depends on your preferences: warm, calmer, cloudy seas, or clear but cold water.

GALAPAGOS
The water temperature is generally about 70° from January to April (the rainy season) and about 66° the rest of the year. Land temperatures also rise during the rainy season, resulting in some uncomfortably hot weather (average daily high is 88°, but it can get much hotter). Visibility tends to drop during the rainy months of February, March, and April. Best months for diving are December and January, then again in May and June. October is probably the worst month, cold and windy. More whale shark sightings are reported during May and June.

INDONESIA
The thousands of Indonesian islands are spread out over mainly an equatorial tropical climate, but the diving season is as complex as everything else about this diverse amalgam of a country. Avoid the wet monsoon season, generally December through the middle of March. The dry monsoon of southeast winds curtails the diving in Flores during July and August. The Moluccas, however, have their wet monsoons the reverse of everyone else, in July and August, and diving should be avoided then. Depending on your specific destination, April-May and September are the best all-round months to dive Indonesia.

PALAU/YAP/TRUK
Air temperatures uniformly remain in the 80s year-round. For land travel, there's little difference between the wet and dry season, although January through March is considered the most comfortable season because of lower humidity and slightly cooler temperatures. Although visibility is slightly reduced by run-off during the July through October monsoons, the wind is also milder during this season, producing flatter seas. Water temperatures remain in the mid 80s year-round. Typhoons are most frequent between August and December but are rare in Palau.

PAPUA NEW GUINEA
PNG's weather is dependent on local topography. Heat and humidity are reasonable considerations. Only in the Highlands does it get cool at night. The driest time of year is May through October, but it rains considerably even then. During the rest of the year, plankton blooms are more common. Although Walindi Plantation Resort accommodates guests year-round, January, February, and March are the wettest months. Some boats beat the rainy weather by moving to the other side of the mountains at Kandrian, miraculously transporting to a dry climate. It's a bit of a steam for the crew, but for guests, it's a quick flight over the mountains by small plane. The water temperature is a wonderfully warm 84 degrees, and the nights are T-shirt comfortable. The heaviest rains occur in the Rabaul area between January and April.

SOLOMON ISLANDS
The Solomons are hot and humid year-round, with the most rain falling between December and March. Annual rainfalls are well above 100 inches, but mountainous islands do produce rain shadows resulting in much less rainfall on some coasts. Between December and April winds blow periodically out of the west (calm spells are broken by storms). The southeast trades blow from the end of April to November. The better months to travel are probably July through September when the rainfall (and therefore malarial mosquitoes), heat, and humidity are lowest, or in November when there's a good chance the seas are flat.