Trip Planning Reference
Trip length, mapped straight through to a headlamp’s spare-battery needs, a clothing-layer recommendation for two representative cave scenarios, and food & water quantities — every number below comes directly from the Headlamp Runtime Calculator, Cave Temperature Layering Guide, and Gear Checklist Generator’s own functions, not a separately typed-up table.
Planning aid, not a substitute for training. This page covers lighting margin, clothing, and food/water quantities only — it says nothing about rigging a pitch, and never will. See the disclaimer.
By trip duration
| Trip duration | Headlamp runtime / set | Spare battery sets | Layers — mild, dry (12°C) | Layers — cold, wet (8°C) | Water / person | Snacks / person |
|---|---|---|---|---|---|---|
| 2h | 6.01h | 1 | 2 | 4 | 1 x 500ml water | 1 snack/meal |
| 4h | 6.01h | 2 | 2 | 4 | 2 x 500ml water | 2 snack/meal |
| 6h | 6.01h | 2 | 2 | 4 | 3 x 500ml water | 2 snack/meal |
| 8h | 6.01h | 3 | 2 | 4 | 4 x 500ml water | 3 snack/meal |
| 10h | 6.01h | 4 | 3 | 4 | 5 x 500ml water | 4 snack/meal |
| 12h | 6.01h | 4 | 3 | 5 | 6 x 500ml water | 4 snack/meal |
Headlamp figures assume one representative lamp (3400mAh, 3.7V, 1.6W draw, 85% driver efficiency, 10% cold derate) carried to cover 2× the planned trip length — run your own lamp’s numbers on the calculator directly. Water and snack quantities are for a horizontal trip, party of four; see the gear checklist table below for how trip type changes the list itself.
Gear checklist size, by trip type
| Trip type | Total checklist items |
|---|---|
| Horizontal | 19 |
| Wet | 21 |
Trip type is what changes a checklist’s total item count — duration and party size instead scale the quantities written inside individual items, like the water and snack figures above. A Vertical / SRT Gear category exists in the underlying generator but is intentionally left out of this table; see the FAQ below for why.
How to read this page
Each row above is a trip of a given length, worked through three of this site’s planning tools at once. The spare-battery figure grows in whole-number jumps because you can only carry whole battery sets, not fractional ones — the underlying runtime-per-set figure stays constant for this representative lamp, and only the number of sets needed to comfortably outlast a longer trip changes. The two layering columns show the same duration pushing the same underlying deficit formula two different ways, depending on whether the cave is mild and dry or cold and wet — the gap between the two widens as the trip gets longer, since a long, cold, wet trip accumulates more of the duration penalty described in this site’s article on layering for a cold, wet cave.
None of this replaces working through your own trip’s actual numbers on the individual calculators — this page exists to show the shape of how trip length moves several planning figures at once, side by side, using representative inputs rather than your specific ones.
Frequently Asked Questions
Where do these numbers come from?
Every figure on this page is computed by calling this site's own headlampRuntime(), caveLayering(), and gearChecklist() functions directly — the same functions behind the Headlamp Runtime Calculator, Cave Temperature Layering Guide, and Gear Checklist Generator. Nothing here is a separately maintained table; if the calculators' logic changes, this page's numbers change with it.
Why is there no vertical/SRT row in the gear checklist table?
This page is a planning reference, not a rigging resource. gearChecklist() can generate a Vertical / SRT Gear category, but this page deliberately leaves it out — that equipment, and how to use it, belongs with hands-on training and a caving club, not a table on a webpage. See this site's article on single rope technique and the disclaimer for why.
Why does the spare-battery-sets column jump the way it does instead of scaling smoothly?
Spare sets needed is a whole-number count — you can't carry a fraction of a battery set — so it's the ceiling of your lighting target divided by one set's real runtime. That's why it holds steady across some duration increases and then jumps by a whole set at others, rather than climbing in a smooth line.
Why do the two layering columns never show a lower recommendation for the cold, wet scenario?
By construction: the cold/wet scenario in this table is always colder, always wet, and never credited a higher activity level than the mild/dry one, so its thermal deficit is never lower. Try the two scenarios yourself on the Cave Temperature Layering Guide with different activity levels — the gap can narrow, but the cold, wet case doesn't come out ahead in this table's fixed comparison.
Planning aid only, built from representative inputs — not a substitute for training, and not a rigging resource. Confirm your own trip’s gear, layering, and lighting with a qualified leader or your caving club, and see the disclaimer for the full picture.
Use it with
- Headlamp Runtime Calculator— run your own lamp’s real capacity, voltage, and draw instead of this page’s representative example.
- Cave Temperature Layering Guide— get a layer recommendation for your actual cave’s temperature and your trip’s real activity level.
- Gear Checklist Generator— build the full, categorised list for your own trip type, duration, and party size.
- Building a Trip Gear List That Actually Fits the Trip — the worked walk-through behind the gear checklist table above.