Freelance Traveller

The Undersea Environment

reviewed by Paul Anuni

This article originally appeared in the January/February 2026 issue.

The Undersea Environment. J. Andrew Keith
Gamelords Lt. (defunct, see https://farfuture.net)
52pp., PDF
US$6.00/UK£4.43 at DTRPG or
available on FFE Apocrypha I CD-ROM

The Keith Brothers have an established reputation for quality Traveller output. This supplement does not disappoint.

The contemporary Traveller core rules (Books 1, 2, 3) allowed for the generation of worlds that had high oceanographic percentages, including worlds with no land area to speak of. Yet there were no rules for actually adventuring in such environments. The Undersea Environment fills that gap nicely; you get essentially everything you need to make adventures on and under water come to life.

Organization

The Introduction claims that the supplement is divided into three parts: Rules, Equipment, Special Encounters and Events. There’s actually a fourth section, Adventures in the Undersea Environment.

The Rules section provides you with the tools you need to manage activities on and under water. This includes not only water-specific skills (such as swimming, diving, and watercraft-operation), but also how to modify other skills when used in a water environment (for example, Blade Combat is at -2). This section goes through all of the skills from the GDW-published rule books and supplements of the time, noting which ones are used normally, which are used in modified form, and which ones Mr Keith couldn’t imagine as being needed or used in the water environment (e.g., steward, streetwise, gambling).

It also provides information for managing the transition between the water and air environments (i.e., avoiding the bends). These rules are specifically called out as being based on contemporary real-world data, but also called out as DO NOT USE IN REAL LIFE. A quick check against current recommendations suggests that forty years has changed the standards; modern dive tables suggest surfacing at only half the rate that Mr Keith’s tables do (that is, real-world takes twice as long to get from a given depth to the surface). Factors such as buoyancy and so on are discussed, as are the effects of gravity, temperature, or other environmental factors. There is also some discussion of things like oxygen use under varying conditions, and nitrogen narcosis is treated as a real problem. The Rules are twenty pages of the fifty-two in the book.

Fourteen pages of Equipment covers a good selection of what is needed to be able to act in the water, from how to breathe to protection from the effects of cold water to improving mobility to weapons and vehicles. Most will be familiar to people who dive in real life, although some high-tech versions and evolutions are included. This section also includes such things as an underwater eight-person lab facility and decompression chambers.

Special Encounters and Events defines types of water environments based on such factors as currents, distance from shore, depth, and so on. They will generally align with the common definitions, but note that calm bodies of water such as those commonly called “coves” or “protected bays” or “lagoons” would fall under this supplement’s definition of “lakes”. It also describes events and hazards and which type of water environment it can occur in (for example, a rip current only occurs in offshore shallows, not in rivers or open deep water). The events described are not all significant hazards; “sandy bottom” or “muddy bottom”, for example, only note a reduction in visibility. There are seven pages of these; they do not include animal encounters (refer to the core rules for creating such encounter tables).

The final three pages of content, Adventures in the Undersea Environment, doesn’t provide any actual adventures, or even adventure seeds, but does suggest some types of adventures that may occur in the water environment, such as salvage, exploration, archaeology, and so on. A creative referee, upon reading this, could also come up with some other ideas.

Production Values

This is the only thing that disappoints even mildly, and even that admittedly is based on modern sensibilities rather than contemporary. The typesetting looks to have been done with an early word processor on an impact (daisy wheel) printer with a fabric ribbon in a font similar to IBM’s Letter Gothic for Selectric typewriters. This is not as easy on the eyes as more modern typesetting and fonts. I wouldn’t mind seeing this re-set using modern software and printing techniques.

The document is text-behind-image, but the text appears to have been badly OCR’d; a simple copy-and-paste gives a high level of typos.

Recommendation

This should definitely be part of your collection. The core rules are good for most adventuring needs, but there are significant differences in underwater adventuring, and this supplement fills the gap that you may not have recognized as present,