Floating · Rechargeable
Sea LiON
Battery-powered diving for two to four divers. Swap batteries to keep the day moving.
From $5,900 · 2 divers
Compare Sea LiON packagesBrownie’s THIRD LUNG™ · Buying guide
Compare Tankless Dive Systems
Which setup fits your dive day? Compare rechargeable Sea LiON, gas-powered The OG, compact BLU3 and built-in BIAS systems by crew size, power source, runtime and starting price.
Complete two-diver equipment is included with every Sea LiON and OG starting configuration.
Choose by the way you dive
Which Brownie’s system is right for you?
A tankless dive system supplies breathing air from a compressor at the surface through hoses to divers underwater. Start with crew size, then choose the power source and portability that fit your boat and dive plans.
| System | Type | Depth | Divers | Runtime | Carry weight |
|---|---|---|---|---|---|
| Sea LiON | Battery · floating | By configuration; four divers: 10–15 ft max* | 2–4 | ~2 hr 15 min (50Ah); ~3 hr (70Ah) | 42 lb unit + 15–18 lb removable battery; 21 lb two-diver gear bag |
| The OG | Gas · floating | Up to 65 ft by configuration* | 2–4 | ~3 hr per fuel tank | 49 lb single-head or 59 lb dual-head unit; 21 lb two-diver gear bag |
| Nomad Mini | Battery · ultra-portable floating | 15 ft max | 1 | ~35–40 min per battery | ~12 lb all-in: ~10.6 lb unit + ~1.4 lb removable battery |
| Nomad | Battery · ultra-portable floating | 30 ft max | 1 | ~45–60 min per battery | ~15 lb all-in: ~12 lb unit + ~3 lb removable battery |
| BIAS | Battery / 24V boat power · built-in | 33 ft max | 2–3 | ~2–3 hr with optional battery; boat power depends on source | 25 lb compressor unit; optional 45 lb battery pack; 21 lb two-diver gear bag |
Sea LiON’s battery can be removed and carried separately from its 42 lb floating unit. Weights are approximate and may change with equipment or configuration; gear bag weights are shown separately for Sea LiON, The OG and BIAS. BLU3 totals include one battery. *Available depth depends on diver count, airflow demand and the exact system setup; confirm the rating in the current manual before diving.
Floating · Gasoline
The OG
The Original Gas Brownie’s. Choose a Briggs single head, Honda single head or Honda dual head.
From $2,900 · 2 divers
Compare OG packages
Compact · Single diver
BLU3 Nomad family
A smaller battery-powered setup for one diver. Compare Nomad Mini and Nomad for your dive plans.
From $1,649 · 1 diver
Compare BLU3 optionsBattery-powered · floating
Sea LiON: charge it, launch it and dive
Sea LiON supplies air to a crew without a gasoline engine at the surface. Its variable-speed compressor responds to demand, while an accumulator tank buffers air between cycles. Remove and swap the battery between dives.
- Complete two-diver starting system with 50Ah battery and charger
- Choose equipment for three or four divers
- Upgrade the main battery to 70Ah or add a spare battery
- Add the optional matching Safety Package for your crew
Current Sea LiON configurations
Compare diver packages and pricing
| Divers | System | Safety Package | System + Safety | Bundle savings |
|---|---|---|---|---|
| 2 divers | $5,900 | +$1,290 | $7,190 | — |
| 3 divers | $6,300 | +$1,600 | $7,900 | $335 |
| 4 divers (10–15 ft max) | $6,700 | +$2,245 | $8,945 | $335 |
System prices include a 50Ah battery and charger, standard downline, basic gear bag, and complete equipment with basic tow belts for the selected divers. The optional Safety Package adds a Spare Air Add-On Kit and SEAC Screen computer for each selected diver.
50Ah included
Approximately 2 hr 15 min runtime.
70Ah primary · +$500
Replaces the included 50Ah battery; approximately 3 hr runtime.
Spare batteries
50Ah +$1,000 or 70Ah +$1,500; each includes a charger and case.
Runtime estimates vary with depth, diver count, breathing demand, conditions and battery age. Check the product page for final configuration, price and availability.
Battery or gas? Choose Sea LiON for rechargeable, push-button use and battery swaps. Choose The OG if you prefer a gas engine that can be refueled during a long dive day. Both start with complete equipment for two divers.
Gas-powered · floating
The OG: choose your engine and crew size
The Original Gas Brownie’s comes with two single-head engine options and a Honda dual-head option for greater compressor capacity. Every starting price includes a complete two-diver setup.
- Briggs & Stratton single head: lowest starting price
- Honda single head: Honda power with a single-head compressor
- Honda dual head: recommended for four divers
Current OG configurations
Choose an engine, then choose your diver count
| Engine + compressor | 2 divers | 3 divers | 4 divers |
|---|---|---|---|
| Single Head · Briggs & Stratton | $2,900 | $3,300 | $3,700* |
| Single Head · Honda | $3,300 | $3,700 | $4,100* |
| Dual Head · Honda | $4,000 | $4,400 | $4,800 |
All prices include the floating system and complete equipment for the selected diver count, with basic tow belts and gear bag. Optional matching Safety Bundle: add $1,100 for two divers, $1,600 for three, or $2,100 for four; each diver gets a Spare Air Add-On Kit and SEAC Screen computer. *For four divers, Brownie’s recommends dual head. Single-head use with four is recommended only for light breathing in extremely shallow water. Check the product page for final pricing and availability.
Already own a Brownie’s? Review the trade-in program when comparing a new Sea LiON or OG. Current eligibility and credits appear on that page.
All five systems · one view
Compare every current dive system
These are starting configurations. The right choice also depends on your depth, breathing demand, crew size and whether you want a floating, portable or boat-installed system.
| System | Starting package | Other package prices | Divers / depth | Power and runtime | Setup |
|---|---|---|---|---|---|
| Sea LiON | $5,900 · 2 divers with 50Ah battery + charger | 3 divers $6,300; 4 divers $6,700. Safety Package +$1,290 / +$1,600 / +$2,245 for 2 / 3 / 4 divers. | 2–4; configuration dependent. Four divers: 10–15 ft max. | Removable battery; approx. 2 hr 15 min with 50Ah or 3 hr with 70Ah | Floating |
| The OG | $2,900 · Briggs single head, 2 divers | Honda single head 2 divers $3,300; Honda dual head 2 divers $4,000. Add $400 per extra diver. Optional Safety Bundle +$1,100 / +$1,600 / +$2,100 for 2 / 3 / 4 divers. | 2–4; up to 65 ft by configuration. Dual head recommended for four. | Gasoline; approx. 3 hr per fuel tank, then refuel | Floating |
| Nomad Mini | $1,649 · 1 diver | Spare batteries, DiveBoost Kit and reserve air available as options; choose on product page. | 1; up to 15 ft | Removable battery; approx. 35–40 min per battery | Compact floating |
| Nomad | $2,199 · 1 diver | Spare batteries and reserve air available as options; choose on product page. | 1; up to 30 ft | Removable battery; approx. 45–60 min per battery | Compact floating |
| BIAS Dive Module | $3,900 · 2 divers; compatible 24V source required | 3 divers $4,300; battery module +$3,000; powered E-Reel +$3,000. Fully equipped 3-diver package $10,300. | 2–3; up to 33 ft | Boat power or optional battery module; approx. 2–3 hr with charged module | Installed aboard |
Runtime estimates are approximate and vary with depth, breathing rate, conditions, battery age and configuration. OG depth and crew size depend on the selected engine and diver setup. BIAS needs an appropriate power source, boat installation and hose-access solution; the base price excludes optional battery module and E-Reel. All prices are before any applicable tax, shipping or installation. Confirm limits in the current manuals before diving.
Installed aboard · boat-ready
BIAS: the dive system that stays with your boat
The Brownie’s Integrated Air System (BIAS) Tankless Dive Module installs aboard your vessel instead of floating behind it. The compressor stays below deck, and the breathing-air hose connects at a side or stern outlet. It is designed for two or three trained divers to a maximum of 33 ft.
- $3,900 starting package: Dive Module and complete two-diver basic kit; uses a suitable 24V source aboard
- Third diver: add $400 for the complete third-diver kit
- Dedicated battery module: add $3,000; approximately 2–3 hours per charge
- Powered E-Reel: add $3,000 for hose deployment and storage; includes a 140 ft hose and stainless hawse fitting
BIAS installation also requires a suitable hose outlet and a clean breathing-air intake. If you do not select the E-Reel, choose the compatible basic thru-hull outlet. Discuss the boat’s power source, installation space and intake location with Brownie’s before ordering.
Quick answers
Tankless dive system FAQs
What is a tankless dive system?
A tankless or surface-supplied dive system keeps its compressor at the surface and delivers breathing air through a hose to the diver. Divers do not carry a primary scuba tank. Proper training, clean intake air, setup and dive planning remain essential.
What is the difference between Sea LiON and The OG?
Both are floating Brownie’s systems that start with equipment for two divers. Sea LiON uses a removable rechargeable battery, variable-speed compressor and accumulator tank. The OG uses a gasoline engine and direct-drive compressor with three engine/compressor choices.
How many people can dive on a Sea LiON or OG?
Both start with equipment for two and can be configured for three or four. Sea LiON’s four-diver configuration has a 10–15 ft maximum depth. Brownie’s recommends the Honda dual-head OG for four divers; four-diver use on a single head is limited to light breathing in extremely shallow water. Air demand varies with depth, exertion and conditions.
How long does a Sea LiON battery last?
Brownie’s estimates approximately 2 hours 15 minutes with the included 50Ah battery and approximately 3 hours with the optional 70Ah primary battery. Actual runtime varies with diver count, depth, breathing demand, conditions and battery age.
Are backup air and dive computers included?
The base Sea LiON and OG prices include dive equipment for the selected diver count, but independent backup air and dive computers are optional. Each matching Safety Package adds one Spare Air Add-On Kit and one SEAC Screen computer per selected diver.
How is BIAS different from Sea LiON?
BIAS installs aboard one boat and uses a suitable 24V source or an optional dedicated battery module. Sea LiON is a portable floating system with a battery included in its starting package, so you can take it between boats or dive locations. BIAS starts at $3,900 for two divers; Sea LiON starts at $5,900 for two divers with a 50Ah battery and charger.
Where can I learn to use a Brownie’s system?
Start with Brownie’s free online training and the current owner’s manual for your model. Get appropriate in-water instruction, dive within your limits and plan for an emergency ascent.
A family of dive systems
Helping people explore underwater since 1969
Brownie’s THIRD LUNG began with floating surface-supplied air systems in 1969. In 2017, we founded BLU3 as a new brand focused on ultra-portable, battery-powered dive systems. Today, Brownie’s THIRD LUNG and BLU3 are both part of Brownie’s Marine Group—giving divers a choice between crew-sized floating systems, integrated boat systems and compact one-diver setups.