On the evening of November 14, 2025, Astrid Pereira stood at the entrance to Ogof Ffynnon Ddu in the Brecon Beacons with five headlamps clipped to a webbing loop on her belt. She had agreed to wear each in turn over the course of a winter's caving in South Wales and the Yorkshire Dales, with a target of 200 hours of actual underground use.
She made the target by April 9, 2026. She had spent 217 hours below the surface, in 38 separate trips, with five lamps in active rotation. Two of them had failed entirely. Two were marginal. One was, against her expectations, still excellent.
The lamps were a Petzl Duo S, a Petzl Swift RL Pro, a Fenix HM65R-T, a Scurion 1300, and a Princeton Tec Apex Pro. The Scurion is the dedicated caving lamp of the test. The other four are nominally general-purpose outdoor headlamps that caving clubs have been known to use.
Pereira logged battery life, beam pattern after extended use, water ingress, switch reliability, and what she called connector integrity — the small, unromantic question of whether the cable between the battery pack and the lamp head still worked at the end of three months of mud, water, and being clipped repeatedly to a harness.
The Princeton Tec Apex Pro failed first. On her third trip, into the wet section of Dan-yr-Ogof, the regulated beam began to flicker at the 90-minute mark. By the fifth trip the lamp was unreliable enough that she carried it as a backup only. Water had entered the battery pack through a seam at the door hinge. Pereira does not blame the manufacturer. Caves are harder than the design brief.
The Fenix HM65R-T lasted longer but failed in a different way. After 78 hours of use the lamp's wide beam dimmed in a single spot, then began to flicker on cold mornings. The cause was a corroded internal contact in the battery compartment. The lamp could be coaxed back to life by removing and replacing the cells, but a caving lamp that needs coaxing is not, in Pereira's phrase, a caving lamp.
The two Petzls held up better. The Duo S, an older design with a separate battery box on the rear strap, ran without fault for the full test. Its beam pattern is unfashionable — a single wide flood with a weak spot — but it never flickered, never failed, and at the end of 200 hours its output, measured against a fresh lamp, had dropped only 8 percent.
The Swift RL Pro was more interesting. Its reactive beam, which adjusts brightness based on what the sensor sees, worked beautifully in the dry passages of Ease Gill in the Dales. In the wet, with mist in the beam, the sensor became confused and the lamp pulsed unpleasantly. Pereira learned to lock the lamp at a fixed output in wet caves, which solved the problem at the cost of the feature.
The Scurion 1300 is in a class of its own and should be evaluated as such. It costs roughly four times what the Petzl Swift costs. It is built to be repaired. Its battery pack is the size of a sandwich and clips to a chest harness rather than a head strap. Its output is regulated to a single brightness for the entire battery life, which on the medium setting is about 36 hours.
After 200 hours the Scurion looked, and worked, as it had at the beginning of the test. Pereira mentions this without surprise. The lamp is engineered for what she was doing. The other lamps were engineered for what most of their owners do, which is hike, run, and read in a tent.
On beam pattern, caving has different requirements from hiking. A caver needs a wide, even flood for navigating breakdown, and a tight spot for picking out a route up a pitch. A single mode lamp is a frustration. The Scurion, the Swift RL Pro, and the Duo S all handle the dual requirement adequately. The Fenix and the Apex Pro do not.
On battery life, the regulated lamps are honest. The Scurion ran for the advertised hours within 4 percent. The Swift RL Pro ran for 81 percent of the advertised time on its highest setting and within 5 percent of the advertised time on its medium setting. The other lamps were more variable.
On switches, the cavers' lore turned out to be correct. Lamps with rotating dials, in cold wet hands, are easier to operate than lamps with capacitive touch surfaces. The Apex Pro's rubber-covered tactile button was the easiest to find in the dark. The Swift's mode button, while reliable, took practice.
On the question of weight on the head, the Scurion is the most comfortable despite being the heaviest, because the battery is not on the head at all. A 90 gram lamp head on a webbing band, after eleven hours underground, is preferable to a 240 gram all-in-one lamp pressing on the forehead.
What Pereira learned, and what she will pass on, is that the dedicated caving lamp is worth the money for people who cave seriously. For the occasional caver, the Petzl Duo S, an older and less glamorous design, remains the right tool at the right price.
She also notes that no headlamp is enough on its own. Caving discipline asks for three sources of light. Pereira will not vary from this and recommends, with some firmness, that no one else should either.
The Apex Pro and the Fenix are now bench warmers in a drawer. The Scurion is back on a hook by the door. Field Lantern will revisit lighting in a different context — winter camping at altitude — later this year.
