NDL vs Scuba Dive Signals
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
NDL
Confirm your diver or freediver status online and save electronic certificates offline. This app offers a free log-book and No-decompression limit planner, along with the latest news from the National Dive League. Professionals can also manage certificates and access the NDL Professional Zone.
- Confirm diver status online
- Save electronic certificates offline
- Free log-book
- No-decompression limit planner
- Latest news from National Dive League
- Manage certificates for professionals
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The official mobile app from NDL, in which you can confirm your status as a diver or freediver online, and also save electronic certificates offline. Free log-book and No-decompression limit planner. With the help of the application you will receive the latest news from the National Dive League, and professionals will receive a convenient tool for ordering certificates and working with NDL Professional Zone from mobile devices. NDL is diving of the XXI century.
Scuba Dive Signals
Access a comprehensive list of underwater hand signals for safe scuba diving communication. Includes a quiz feature to test your knowledge of signals recognized by major training agencies.
- List of recognized dive hand signals
- Signals from PADI, NAUI, SSI
- Quiz feature to test knowledge
- Safety communication focus
- Creative Commons licensed images
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Access a handy list of dive signals to safely communicate underwater while scuba diving. This contains a list of hand signals generally recognized by the Recreational Scuba Training Council and its member agencies (PADI, NAUI, SSI, and more). Once you've studied up, you can quiz yourself on what you've learned-- the app will show a series of five dive signal descriptions and give you a choice of four different pictures-- only one will match, so choose wisely! As always, safety is paramount when scuba diving, so be sure you are your diving partners are clear on their meanings before diving. The author of this app does not assume and hereby disclaims any liability to any party for any loss, damage, or injury, including death, caused by errors or omissions, whether such errors or omissions result from negligence, accident, or any other cause. The information in this app is meant to supplement, not replace, proper scuba diving training. Scuba diving poses some inherent risk. Never dive without proper training and certification! The images used in this app are used via the Creative Commons Attribution-Share Alike licenses, and are credited as follows: Creative Commons Attribution-Share Alike 3.0 Unported license (https://creativecommons.org/licenses/by-sa/3.0/deed.en): Original author: Thomei08 Dive hand signal-cold.plain.svg Dive hand signal-look.plain.svg Dive hand signal-tink.plain.svg Dive hand signal-ear.plain.svg Original author: Peter Southwood Dive hand signal OK 1.png Dive hand signal OK 2.png Dive hand signal OK surface 1.png Dive hand signal OK surface 2.png Dive hand signal Stop.png Dive hand signal Turn Around.png Dive hand signal Which Way.png Dive hand signal Boat.png Dive hand signal Buddy up.png Dive hand signal Hold on to each other.png Dive hand signal Lead and follow.png Dive hand signal Level out.png Dive hand signal Slow down.png Dive hand signal Give me air.png Dive hand signal Emergency Out of air.png Dive hand signal Help surface 1.png Dive hand signal Dont know 1.png Dive hand signal Danger there.png Dive hand signal Pressure.png Dive hand signal Bubbles.png Dive hand signal Cut.png Dive hand signal Safety stop.png Dive hand signal Entangled.png Dive hand signal Silt.png Dive hand signal Cramps.png Dive hand signal Reserve.png Dive hand signal Time up.png Dive hand signal Fetch surface 1.png Dive hand signal Turn dive.png Dive hand signal Stuck.png Creative Commons Attribution-Share Alike 4.0 International license (https://creativecommons.org/licenses/by-sa/4.0/deed.en): Original author: Peter Southwood Dive hand signal Ascend to stop.png The licensors do not in any way endorse the author of this app or usage.
Screenshots
Verdict
The clearest difference is review sentiment: Scuba Dive Signals at 100% against NDL's 67%. NDL's advantage is update cadence (every 5 months vs every 42 months) and iOS requirement (12.0 vs 15.0). On price, ads, in-app purchases and monetization model there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
NDL ships an update every 5 months, Scuba Dive Signals every 42 months. Both last shipped on November 3, 2026.
| Parameter | NDL | Scuba Dive Signals |
|---|---|---|
| Price | Free | Free |
| Rating | — | 5.0 (3 ratings) — better |
| Positive reviews | 66.7% of reviews | 100.0% of reviews — better |
| Number of ratings | — | 3 — better |
| Update frequency | Every 5 months — better | Every 42 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 12.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 17 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | NDL, UCH | Eric Hamiter |
Customer experience
NDL
Scuba Dive Signals
In-app purchases
NDL
No in-app purchases
Scuba Dive Signals
No in-app purchases








