When divers move from night dives into caves, wrecks, or other deep and high-demanding dive activities, lighting matters the most. It becomes part of how you;understand the situation and be aware of your surroundings, and get out safely if something goes wrong.
Therefore, instead of asking which torch has the highest lumen number, it makes more sense to ask: Will this light still do its job at the end of the dive—and what happens if it fails?
This guide explains the difference between canister and handheld lights, then shows where a modular system such as OrcaTorch FlexDive is the perfect choice as primary light for technical dive and also video light for underwater photography.
Why Backup Lights Matter
A primary light is the one you use for most of the dive. It helps you see the direction, check your surroundings, communicate with your team, and find your way back.
Backup lights are in great difference, which exist for the moment your primary stops working. The role to pick a backup light is that they should be easy to reach with one hand, simple to switch on, and reserved for emergencies.
For cave diving, training standards make this especially clear. TDI Full Cave Diver requires one primary and two backup lights per diver, with enough burn time for the planned dive. Students also practise what to do if the main light fails. For ordinary night diving, it is recommend ed to have at least a main light and one backup torch.
In short, backup lights are not optional extras—they are the safety net that lets you keep seeing, navigate, and get out safely if your main light does not work.
Canister and Handheld
A canister light separates the battery from the light head. The battery is usually worn on the hip, while the light head is held in the hand or mounted on a handle. A cable connects the two.
A handheld light puts the battery, light head, and switch into one self-contained unit. There is no cable to route or manage.
|
Factor |
Canister |
Handheld |
|
Battery location |
Worn on the body |
Inside the light |
|
Cable |
Yes |
No |
|
Weight in the hand |
Lighter, because the battery is on the hip |
Heavier |
|
Best suited to |
Longer dives, exploration |
Shorter technical dives, travel |
|
Main trade-off |
cable management |
Lower power capacity |
Canister lights became popular among cave and exploration divers because the body-mounted battery can reserve more capacity and ease the burden on hand. Besides, if the light head is dropped, the cable keeps it connected to the diver rather than letting it disappear into the dark.
Handheld lights used to be seen mainly as backup lights or simple lights for casual recreational diving. But that has changed. Thanks to modern rechargeable batteries and LED technology, today’s compact handheld lights can be bright enough and last long enough to do jobs that used to require a larger canister light.
In short, canister lights prioritize longer runtimes and a lighter weight in hand at the cost of cable management, while handheld lights prioritize simplicity and portability at the cost of battery capacity. So the better choice depends on the dive, not on which type is “more professional.”
Spot and Flood Beam
A spot beam is narrow and focused. It reaches farther, making it useful for seeing a guideline in the distance, pointing out a specific area, or signaling a companion.
A flood beam is wide and soft. It lights up the area around you, helping you know the environment and see more of what is beside you rather than only directly ahead.
For underwater photography and video, flood light is especially useful. Unlike a narrow beam, it spreads even light over a wider area, which offers more natural looking on photos and videos. Although in murky water, a very wide flood can light up floating particles and create backscatter. In those conditions, a narrower beam or lower output may actually give you a clearer view.
A dual beam dive light will be ideal to solve this by putting both spot and flood beam in one light. For example, OrcaTorch FlexDive uses an 8° spot for distance and signaling, and a 150° even flood for surroundings and general illumination. You can use these 2 light either on its own, or use them simultaneously. A dual-beam light gives you both options without carrying two separate lights.
How to Choose a Technical Dive Light
A high lumen number is easy to notice, While runtime is what determines whether the light is actually suitable for your dive.
Before buying, look at the output level you expect to use most often. Then check how long that level lasts. A light that runs for 65 minutes at max output may be excellent for short daytime dive, but it is not the right primary for a three-hour dive unless you have a clear plan for lower settings and reserves.
Plan battery life around the whole dive, including the exit, ascent, decompression, and a safety margin—not just the time you expect to spend at the bottom.
Low-battery protection and overheat protection can also reduce output. Those features protect the electronics, but they are not a substitute for carrying backups and planning enough runtime.
Finally, consider the practical details: depth rating, size, underwater weight, whether the switches work with gloves, charging method, and airline rules for spare batteries.
FlexDive as a Modular Example
Most dive lights are bought as a fixed product: handheld or canister, configured for sidemount or backmount. If your diving changes, you often need to buy another complete light.
A modular system works differently. The light head, battery, and cable are all separate components that can be mixed and matched as needed. So you can build the setup that suits each dive.
FlexDive can be set up in three ways:
· Handheld: light head plus B49 battery and an adjustable handle. This is the simplest, cable-free setup.
· Canister: light head plus B98 battery and connection cable. This suits longer cave or wreck dives and can be adapted for backmount or sidemount.
· Video: the same light head and B98 battery mounted to a compatible camera support.
These are three configurations of the same primary light. The most convenient and cost-effective part is that the video and canister versions share the same B98 battery. If you already own one, adding the cable or camera-mount components is all it takes to turn it into the other setup.
FlexDive puts both beams in one head: an 8° spot for distance and signalling, and a 150° flood for wide, even coverage. Each can be used alone, or both can be turned on together
FlexDive Canister
|
Mode |
Output |
Runtime |
|
Flood + Spot |
8,000 lm |
2h 25min |
|
Flood, high |
6,200 lm |
2h 40min |
|
Flood, mid |
2,800 lm |
6h 20min |
|
Flood, low |
1,200 lm |
12h 10min |
|
Spot, high |
3,000 lm |
5h 10min |
|
Spot, low |
1,000 lm |
22h 35min |
FlexDive Handheld
|
Mode |
Output |
Runtime |
|
Flood + Spot |
8,000 lm |
1h 5min |
|
Flood, high |
6,200 lm |
1h 20min |
|
Flood, mid |
2,800 lm |
3h 5min |
|
Flood, low |
1,200 lm |
6h 15min |
|
Spot, high |
3,000 lm |
2h 45min |
|
Spot, low |
1,000 lm |
10h 25min |
The 8,000-lumen setting combines both beams at their highest levels.
FlexDive is designed to keep its brightness stable for most of the dive. It does not slowly fade as the battery drains. When the battery is almost empty, it steps down to a lower mode instead—so you get a clearer warning that it is time to manage your remaining battery life.
The FlexDive is rated to 150 metres. Its head diameter is 74mm and its body diameter is 58mm. The canister version is 231mm long, while the handheld version is 151mm.
The handheld weighs 848g on the surface and 365g underwater. The canister weighs 1,243g on the surface and 630g underwater. In the water, much of the difference comes from where the battery sits: on your hip in the canister setup, or inside the light in the handheld setup.
Operation is deliberately straightforward：
- Long-press the right switch to power the light on, then click it to cycle through the 150° flood beam: Low → Mid → High.
- The left switch works only after the light is powered on; click it to cycle through the 8° spot beam: Low → High → Spot + Flood together.
- Once levels have cycled through, click the switch to power off. The battery indicator sits between the two.
The titanium switches are designed to work with gloves, and a safety lock helps prevent accidental activation during transport.
Both versions charge by magnetic tail charger or USB-C PD. Magnetic charging takes about 2.5 hours for the B49 and about 5 hours for the B98. The battery packs can also work as power banks for compatible devices, which can be useful on or remote trips.
Which Setup Suits You?
Choose the handheld version if you want a cable-free setup, travel often, dive sidemount, or your planned runtime fits comfortably within its battery capacity.
Choose the canister version if you dive longer caves or wrecks, use a DPV, or prefer to keep the battery on your body rather than in your hand.
Choose the video version if underwater imaging is a major part of your diving. The wide flood beam is designed for broad coverage, while the spot remains available for navigation and signalling.
If you expect to need both video and canister setups, starting with either B98 configuration makes sense. Because they share the same battery, the second configuration mainly requires the appropriate cable or mounting components.
The Decision in One Paragraph
A handheld makes sense when you value simplicity, travel lightly, or your dive fits within its runtime. A canister makes sense when you need more capacity, want the battery on your body, or already dive a configuration where a cable system works well. If your diving covers both, a modular platform lets one light head move between setups instead of forcing you to choose once and replace everything later.
Whatever format you choose, the essentials stay the same: enough burn time for the full dive, backups that are independent and practised, and a primary light you can operate confidently under pressure.
Compare configurations and current specifications: view the FlexDive series.
FAQ
Can a handheld replace a canister as a primary light?
Yes. If its runtime at the output you will actually use covers the whole dive with margin, a handheld can work as a primary. Canisters remain common for longer exploration dives and situations that need more battery capacity.
How many lights do cave divers carry?
TDI Full Cave requires one primary and two backups—three battery-powered lights per diver.
Should I choose spot or flood?
Use spot for distance, signalling, and detail. Use flood for surroundings and photo or video work. A dual-beam light lets you do both without carrying separate lights.
Does constant output mean the light never dims?
No. It means brightness stays stable through most of the battery’s usable range, then steps down at low charge rather than fading gradually.
What do I need for each FlexDive configuration?
Handheld uses the light head plus B49. Video uses the light head plus B98. Canister uses the light head plus B98 and umbilical cable. Video and canister share the same B98 battery.
Can I fly with the B49 or B98 battery?
Both are below the common 100Wh carry-on threshold. Spare lithium batteries should travel in carry-on baggage with terminals protected; check your airline’s current rules before flying.