Pacific Diving

Many of the world’s scuba divers consider Pacific diving the “best of the best”, and with good reason.

This page of our website presents information on key aspects of Pacific diving, along with our picks for the top dive vacation destinations at which to explore coral reefs of the region. 

The Pacific Ocean

The Pacific Ocean proper is by far the largest of the world’s oceans, filling the vast expanse between Asia and Australia to the west and the Americas to the east. By international convention (as of the year 2000), the Pacific Ocean is bounded to the south by the Southern Ocean at 60°S latitude.

The Equator divides this vast ocean realm into the North and South Pacific.

The Pacific covers about 1/3 of the Earth’s surface, an area twice the size of the Atlantic Ocean and greater than that covered by all the continents combined.

It is one of three major subdivisions of the larger Indo-Pacific region of coral reef development discussed elsewhere on this website.

Diving Environment: Pacific Coral Reefs

Coral Reef Types

The Pacific contains an abundance of all three major coral reef types (atolls, barrier reefs, and fringing reefs).

There are hundreds of atolls (see photo, left) in the Pacific Ocean, making them one of the most common type of open ocean reef in the region.

Likewise, barrier reefs are considerably more widespread in the Pacific Ocean than in the Caribbean region.

Fringing reefs are not nearly as prevalent in the Indo-Pacific region as a whole as in the Caribbean, but are quite common in many areas.

Fringing reefs are well represented in the high islands of French Polynesia, and off east Africa,

Distinctive Characteristics

Along with the greater balance in the relative numbers of major reef types, the incredible biodiversity housed on Pacific coral reefs is one of the biggest differences between reefs of this region and those of the Greater Caribbean.

There are also other major differences in certain coral reef characteristics between coral reefs of the Pacific region and those of the Greater Caribbean region.

Most healthy Pacific reef surfaces are composed nearly exclusively of hard coral colonies, unadorned by extensive growth of octocorals and large sponges as is so commonly the case with shallow Caribbean coral reefs.

Another major difference is the widespread presence of a prominent algal ridge on the seaward margin of Indo-Pacific coral reef crests. In comparison, algal ridges are relatively rare and poorly developed on Caribbean reefs.

Pacific coral reefs also often contain extensive reef flats composed of consolidated coralline sands situated immediately shoreward of the reef crest, a feature rarely seen in the Caribbean region.

Biodiversity

The diversity of reef life that can be found on the most diverse Pacific coral reefs is truly staggering, with perhaps as many as 700 or so species of corals present, along with perhaps 3,000 kinds of coral reef fishes.

However, all these species are not present throughout the entire region. Rather, most species are restricted (endemic) to particular (and sometimes quite small) portions of the region. For example, about 25% of all the inshore fishes found in Hawaii are endemic (found nowhere else).

Thus, although there is a common thread of like species throughout most of the region, many distinctive sub regions exist. Because of its sheer size and remoteness, much of the Pacific Ocean even today remains largely unexplored, and new species of fishes and other reef life are continually being discovered.

The center of biodiversity for the Indo-Pacific region as a whole is a rough triangle encompassing an area extending from the southern Philippines to eastern Indonesia and western New Guinea. The farther a reef is located from this center, the correspondingly fewer species of fishes, coral and other reef life will be found.

The Pacific Ocean proper includes most of this area, except for most of the reefs around the islands of Indonesia, which are located within the Indian Ocean.

There are two likely reasons for the far higher biodiversity found on Pacific coral reefs and their Caribbean counterparts.

First, the sheer size of the region occupied by Pacific coral reefs, as well as the length of coastline where corals can successfully grow is much greater than in the Caribbean, allowing more room and opportunities for species diversification.

Secondly, most Pacific coral reefs did not experience the severe temperature changes the Caribbean region suffered during the Pleistocene ice ages. This likely resulted in more Indo-Pacific species of coral, fishes, and other types of reef life surviving into the current post-glacial epoch.

Best Pacific Diving Destinations

While there is a considerable area of coral reef development in the North Pacific stretching from the Hawaiian Island chain to southern Japan, the most abundant and richest coral growth by far is in the South Pacific.

There are two main reasons for this. First, the South Pacific contains many more islands around which coral reefs can develop. Second, the South Pacific is much closer to the center of marine biodiversity for the Indo-Pacific region as a whole.

Thus, when considering what to include in our list of “top picks” for Pacific diving, we narrowed our list to several choices in the South Pacific.

Our selection of the “Best Pacific Diving Destinations” is based upon the same Selection Criteria detailed on our page “Caribbean Diving” and used for our “best diving destination” picks for all regions of coral reef development included in this sub-section of “Best Coral Reef Diving”.

Using these standards, we have chosen the Great Barrier Reef (Australia), Vanuatu, and Palau as our choices for the best diving destinations at which to explore coral reefs of the South Pacific region.

In this section of our website, we have devoted a separate page to each of these superb Pacific diving destinations.

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