Shearwater Research Peregrine Dive Computer: Specifications and Who It Suits

The Shearwater Research Peregrine is a intermediate tier dive computer in the $500 to $600 band. The computer that made Shearwater firmware affordable. It runs the same Bühlmann implementation with user set gradient factors as the technical units above it, on a colour screen, with a two button interface that is hard to mis-drive with cold hands.

The specifications below are the manufacturer's published figures. Where we could not confirm a figure against the maker's own documentation, the row is left out rather than guessed at, which is why some units on this site show fewer rows than others. On a page whose readers can check the work, a missing row is better than an invented one.

What are the Shearwater Research Peregrine specifications?

Who is the Peregrine for?

A diver buying one computer for the next decade who wants a decompression model they can configure and read rather than a black box.

An intermediate tier computer is the buy-once purchase. It costs enough to hurt and little enough that you will not replace it, and the features it adds over a beginner unit, usually a better display and a model you can configure, are ones you will still be using in ten years. This is the tier where most divers who dive regularly should be shopping.

Who should not buy the Peregrine?

Anyone who needs tank pressure on the wrist. The Peregrine has no air integration at all, and if that is the feature you want you are looking at the Peregrine TX or the Tern TX.

That is the more useful half of any specification page. Computers in this category are close enough on the things that matter, tracking depth and time and applying a model, that the deciding factor is usually a mismatch rather than a ranking: a screen you cannot read without glasses, a menu system nobody near you can teach, or a feature set aimed at diving you do not do. Compare against the alternatives at the bottom of this page before deciding.

What does Bühlmann ZHL-16C with Gradient Factors actually mean on a dive?

A decompression model is a mathematical description of how quickly inert gas moves into and out of body tissue, used to calculate how long you can stay at a depth before a direct ascent stops being acceptable. Every computer runs one, they disagree with each other, and the disagreement is real rather than cosmetic.

Buhlmann ZHL-16C models sixteen theoretical tissue compartments with different gas uptake rates. The gradient factor pair layered on top of it, usually written as something like 40/85, sets how close to the theoretical limit the computer will let you go, low first and high second. The practical consequence is that conservatism becomes a setting you can see and justify rather than a level the manufacturer chose silently. That transparency is why the same implementation appears on technical units costing several times as much.

Whichever model a computer runs, the rule is unchanged: your own computer supersedes any published table, two computers on the same dive can legitimately disagree, and a buddy pair runs the dive on the more conservative of the two. The algorithm comparison covers the trade in detail, and the no-decompression limits table shows how far apart published figures can be.

Does the display suit the diving you do?

The Peregrine uses a full colour lcd. Display technology decides legibility more reliably than screen size does, and legibility is the specification that actually matters at depth.

A colour screen separates warnings from data by hue rather than by position, which is quicker to read when you are task loaded, and it stays legible in the low contrast blue-green light of deeper water where a segment display can wash out. The cost is battery, which is why colour units are usually rechargeable, and price.

Whatever the screen, check one thing in the shop before you buy: can you read it at arm's length without your glasses, in dim light, at a glance? Presbyopia arrives for most divers in their forties and it is the single most common reason a computer gets replaced.

How does air integration work on this unit?

The Peregrine has no air integration. Cylinder pressure comes from a mechanical submersible pressure gauge on a hose, which is the standard recreational arrangement and is entirely adequate: it needs no battery, no pairing and no line of sight. If pressure on the wrist is the feature you want, the answer is a different computer rather than an accessory, and the air integrated roundup covers the options.

Air integration does not change how much gas you have or how fast you use it. That is your own respiratory minute volume, and it is worth knowing as a number rather than as a feeling. The SAC rate calculator works it out from one logged dive, and the gas planning calculator turns it into a reserve and a turn pressure.

Gauge mode turns the computer into a depth and time instrument with no decompression calculation at all. It exists for divers running their own tables or their own plan, and it is not a way to dive past a no-stop limit without the computer complaining. Using it that way is technical diving without the training, and it is the single most common misuse of the mode.

What should you check before you buy?

• Can you read it? At arm's length, in dim light, without glasses. This is the most common reason a computer is replaced, and no specification captures it.
• Can someone near you teach it? A unit your local shop rents and services is worth more than a slightly better one nobody around you has used.
• Does the battery arrangement suit your travel? A rechargeable unit needs a charger, a cable and a plan on a liveaboard, and it has no hatch to flood.
• Is the price band real for you? This is the middle of the market, which is where most divers who dive regularly should be shopping.
• Are you buying capability or permission? A computer that supports trimix does not qualify you to dive it. Training comes first, always.

Related reading

• All dive computer specifications, A to Z
• Best dive computers overall
• How to choose a dive computer
• Buhlmann versus RGBM
• Nitrox MOD calculator
• The buy-once scuba setup