Methodology

How rankings work

The directory is ordered by reviews — specifically, by how much evidence exists from divers who trained with a centre or instructor. Nothing else about a listing moves it up: not how complete the profile is, not how long it has been listed, not which agency it teaches. The one exception, stated first below, is paid placement.

The order, step by step

  1. 1

    Featured listings come first — and are labelled

    A listing on a paid placement is shown above everything else in the results it matches, with a gold frame and a Featured marker. It never appears in a search it does not match, and paying for it does not change any of the review counts described below. See how placement works.

  2. 2

    Listings with review evidence rank above listings with none

    A centre or instructor with no reviews anywhere sits below every listing that has some.

  3. 3

    Then, the more review evidence, the higher

    A listing's evidence is the number of reviews about technical or cave diving that we have found for it, plus the number of reviews left on TecDiveTools. Each review counts once, whichever of the two it came from.

    Only technical reviews count from outside sources. A shop with a busy reef operation can have hundreds of reviews thanking it for a day trip; those say nothing about its decompression training, so they do not move it up.

  4. 4

    The star rating is a tie-breaker, not the ranking

    We rank on how much evidence exists, not on the average score. A four-star average from forty technical students says more than a five-star average from two, and an average and a count measure different things — adding them together would mean neither. The rating only decides the order between listings holding the same amount of evidence.

How to improve a listing's position

Get more of the divers you have trained to leave a review. That is the whole of it. Where they leave it decides how quickly it counts:

On TecDiveTools — counts within minutes

A review left on your listing here counts towards its position as soon as the directory next refreshes, which is within a few minutes. This is the fastest way to move up.

Google Maps, ScubaBoard, Reddit and others — counts at the next harvest

Public reviews are collected and read in batches, roughly every six months. They count just as much, but only once they have been picked up.

Reviews must be genuine

Leaving a review on TecDiveTools needs a signed-in account. Reviews appear straight away, but we may contact the reviewer to confirm they trained with the centre or instructor — a certification card or booking confirmation is usually enough — and reviews we cannot verify are removed. Do not review yourself, and do not pay or reward anyone for a review: both get removed.

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