- What This Cheat Sheet Covers
- LST Credential at a Glance
- Core Knowledge Areas You Must Know
- Registration, Fees, and Logbook Mechanics
- Question Style and Exam Format
- Field Days and Experience Requirements
- One-Week Focused Review Schedule
- Who Hires LSTs and Why It Matters for Your Prep
- Common Mistakes Candidates Make
- FAQ
- The LST card requires the online ADCI exam plus at least 100 field days as an assistant LST.
- Renewals and new applications both go through ADCI's Skill N Depth online system, and cards last five years.
- Core knowledge spans diving physics/physiology, basic saturation theory, safe operations, and equipment-specific training.
- Valid CPR and first aid plus a maintained personal logbook under the 6.5 Edition Consensus Standards are non-negotiable.
What This Cheat Sheet Covers
This is a single-page reference for the Life Support Technician (LST) credential administered by the Association of Diving Contractors International (ADCI). It's built for candidates who already have field experience and just need a fast, accurate recap of what the credential actually requires before they sit the online exam. It is not a substitute for full preparation - for that, pair this page with the LST Study Guide 2026 and a deeper look at the LST Exam Domains 2026 guide.
Everything below is organized around what ADCI actually verifies: your online exam performance, your logged field days, your equipment-specific training, and your safety certifications. If you're unsure whether you even qualify to sit the exam yet, check the LST Requirements 2026 breakdown before you spend time on this cheat sheet.
LST Credential at a Glance
Before drilling into content, lock in these mechanical facts. They come up constantly in forums and get misremembered - this table is the corrected version.
| Requirement | Detail |
|---|---|
| Administering body | Association of Diving Contractors International (ADCI) |
| Application/exam platform | ADCI's Skill N Depth online system |
| Exam format | Online ADCI LST examination |
| Minimum field experience | At least 100 field days as an assistant LST |
| Additional training | Equipment-specific training and experience; required industry, regulatory, or manufacturer training |
| Safety certifications | Valid CPR and first aid |
| Documentation | Personal logbook under the current 6.5 Edition International Consensus Standards |
| Card validity | Five years |
| Renewal process | Online examination required for both new applicants and renewals |
Note the last row - this is where a lot of experienced techs get caught off guard. Under current classification rules, renewal is not a paperwork-only process; you go back through the online exam. If your card is approaching its five-year mark, start reviewing now rather than waiting for a lapse.
Core Knowledge Areas You Must Know
ADCI expects LST candidates to demonstrate working knowledge across a defined set of technical areas. Think of these as your content pillars - everything you study should map back to one of them.
Diving Physics and Physiology
Candidates must show working knowledge of how pressure, gas behavior, and human physiology interact during dive and chamber operations.
- Pressure-volume relationships and how they affect gas supply calculations
- Physiological effects of pressure changes on divers and chamber occupants
- Why physiology knowledge directly informs life support decision-making, not just theory recall
Basic Saturation Theory and Safe Operations
Since LSTs support saturation and surface-supplied operations, you need a working - not academic - grasp of saturation principles and how they translate into safe day-to-day practice.
- Core saturation concepts and how they shape chamber and bell operations
- Safe operating procedures during transitions, lock-outs, and emergency scenarios
- How safe-operations knowledge ties back into the field-days requirement - this is learned by doing, not just reading
Equipment-Specific Training
ADCI requires equipment-specific training and experience, meaning your knowledge must match the actual systems you've worked with in the field.
- Manufacturer procedures for the specific life support systems you're logging hours on
- Regulatory requirements tied to the equipment class you operate
- Documentation showing you completed the required industry or manufacturer training, not just informal exposure
Safety Certifications and Standards Compliance
Beyond technical knowledge, ADCI verifies that your safety credentials and documentation are current and standards-aligned.
- Valid CPR and first aid certification held at the time of application
- A personal logbook maintained under the current 6.5 Edition International Consensus Standards
- Consistency between your logged field days and your claimed equipment experience
For a section-by-section walk-through of how these areas map to actual exam content, the LST Exam Domains 2026 guide goes deeper than this summary allows.
Key Takeaway
Study each content area alongside the equipment and procedures you've actually logged field days on - ADCI's design assumes your exam knowledge and your field experience reinforce each other.
Registration, Fees, and Logbook Mechanics
Registration for the LST exam runs entirely through ADCI's Skill N Depth online application and examination system. There's no paper application track - everything from initial submission to scheduling to results happens digitally. A few mechanics worth locking in:
- New applicants and renewals both test online. Current classification rules do not allow a renewal-by-experience-only path - you sit the online exam either way.
- Your logbook is a compliance document, not just a personal record. It must reflect the current 6.5 Edition International Consensus Standards, and it's what ADCI uses to verify your field days and equipment exposure.
- Cards expire on a five-year cycle. Track your issue date so you're not caught scheduling a renewal exam at the last minute.
If you're trying to budget for the process - application fees, exam costs, and any training you still need - the LST Certification Cost 2026 breakdown lays out the full pricing picture separately from this cheat sheet.
Question Style and Exam Format
The LST exam is delivered online through Skill N Depth, which means candidates should expect a computer-based, scenario-driven question style rather than pure recall. Expect questions that:
- Present a field situation (a chamber transition, an equipment fault, a physiological symptom) and ask you to identify the correct or safest response
- Test applied understanding of physics and physiology concepts rather than isolated formulas
- Reference safe-operations judgment calls that only make sense if you've actually worked assistant LST field days
- Occasionally reference manufacturer or regulatory procedures tied to specific equipment classes
Because the format leans on applied judgment, rote memorization of terms tends to underperform compared to reviewing actual field scenarios. If you want a realistic sense of how tough this actually feels in practice, read How Hard Is the LST Exam? Complete Difficulty Guide 2026 before assuming your field experience alone is enough.
Knowing exactly what score you're aiming for also changes how you allocate review time. Confirm the current benchmark in the LST Passing Score 2026 guide so you're not over- or under-preparing on any single content area.
Field Days and Experience Requirements
The 100-field-day minimum as an assistant LST is arguably the most misunderstood part of the credential. Candidates sometimes treat it as a formality; ADCI treats it as the backbone of your eligibility. A few clarifications worth keeping on this cheat sheet:
- Field days must be logged as an assistant LST - general dive-team time doesn't automatically count unless it fits that role.
- Equipment-specific experience needs to be documented alongside general field days, not assumed from tenure.
- Your logbook format and content need to align with 6.5 Edition Consensus Standards expectations, so retroactively fixing a poorly kept logbook can delay your application.
If any part of your eligibility path is unclear - especially how field days, training, and the exam fit together - the LST Requirements 2026 page is the more complete reference; this cheat sheet assumes you already meet the basics.
One-Week Focused Review Schedule
This isn't a full study plan - it's a compressed final-review structure for candidates who already have field days logged and just need to consolidate knowledge before exam day. Spend more time on whichever domain feels weakest.
Physics and Physiology Refresh
- Rework pressure-volume and gas-behavior problems until calculations feel automatic
- Review physiological effects at each phase of a dive/chamber cycle
Saturation Theory and Safe Operations
- Walk through transition and lock-out procedures step by step
- Cross-check safe-operations steps against your own logged field experience for gaps
Equipment-Specific and Regulatory Review
- Confirm manufacturer procedures for the exact systems on your logbook
- Re-read any regulatory training materials tied to your equipment class
Scenario Practice and Final Check
- Run timed scenario-style questions covering all domains, not just your strongest one
- Verify CPR/first aid currency and logbook completeness before submitting through Skill N Depth
Spaced review across a short window like this works well here specifically because the exam rewards applied judgment - cramming isolated facts the night before tends to backfire on scenario-based questions. For a longer-horizon plan that starts weeks out instead of days out, see the full LST Study Guide 2026.
Who Hires LSTs and Why It Matters for Your Prep
Commercial diving contractors, saturation diving companies, and offshore support operations hire certified LSTs to manage chamber operations, gas systems, and diver life support during saturation and surface-supplied work. Because hiring decisions often hinge on which equipment systems you're certified and experienced on, your exam prep should mirror your actual (or intended) equipment specialization rather than a generic overview.
This is also why the credential's value gets discussed in terms of career trajectory rather than just a pass/fail milestone. If you're weighing whether the time investment is worth it against your career goals, the Is the LST Certification Worth It? ROI Analysis 2026 article and the LST Salary Guide 2026 both address that from different angles.
Common Mistakes Candidates Make
- Treating the exam as pure recall. The scenario-driven format punishes memorization without applied understanding.
- Underestimating the logbook requirement. A logbook that doesn't align with 6.5 Edition Consensus Standards can stall an otherwise-ready application.
- Letting CPR/first aid certification lapse. These must be valid at time of application, not "recently expired."
- Assuming renewal skips the exam. Current rules require the online exam for renewals too - don't plan around an outdated process.
- Ignoring equipment-specific gaps. General field-day totals don't compensate for missing training on a specific system you're claiming experience with.
Running through realistic scenario questions ahead of time - for example, through the practice sets at LST Exam Prep - helps surface these gaps before they show up on exam day rather than after a failed attempt. It's also worth reviewing aggregate outcome data, if you want context on how candidates generally perform, in the LST Pass Rate 2026 analysis.
Key Takeaway
Most avoidable failures trace back to logbook or documentation issues, not knowledge gaps - audit your paperwork with the same seriousness you give the exam content.
Frequently Asked Questions
The credential requires at least 100 field days as an assistant LST as part of overall eligibility, alongside equipment-specific training, required industry or manufacturer training, and current CPR/first aid. Confirm the exact sequencing for your situation against the LST Requirements 2026 guide.
Current classification rules require an online examination for both new applicants and renewals through ADCI's Skill N Depth system - there isn't a separate, lighter renewal-only path described in current requirements.
Five years. Track your issue date and start reviewing well before that window closes, since renewal also requires passing the online exam again.
At minimum: diving physics and physiology, basic saturation theory and safe operations, equipment-specific training tied to your logged systems, and compliance items like a current logbook and valid CPR/first aid.
Working through structured practice questions - such as the sets available at LST Exam Prep - is a practical way to get comfortable with the scenario-based format before attempting the real online exam.