the workhorse
Sugar kelp
Fast, dense, and cold-water loyal. The backbone of every line.
s. latissima
Open-ocean farming, at scale
grownunderwater.
Kelp is an open-ocean farming platform — we seed, grow, and harvest seaweed at scale on longlines, and publish every reading from the water.
● line 7 · sugar kelp · 14 m down
01
How it works
Three steps. No fertilizer, no feed, no freshwater.
/ 01
Seed the spool
In the hatchery, we settle microscopic spores onto twine and wind it onto spools bound for the water.
/ 02
Grow on the line
The spooled line is married to a longline, where the blades grow a metre a month on nothing but current and cold.
/ 03
Harvest & bale
Late spring, the boats winch the lines and the crop comes up — washed, dried, and baled by nightfall.
02
The longline
One rope, a thousand blades, all hanging down.
01
Seed
spores settled in the hatchery
02
Grow
blades, a metre a month
03
Harvest
lines winched in late spring
04
Rest
the lease breathes till winter
03
Everything but the noise
What the farm runs on.
Longline systems
Buoys, anchors, and a single rope — no frames, nothing to rot.
Live telemetry
Depth, temperature, and growth from every line, every 15 minutes.
Carbon tracked
Every tonne grown is weighed, sampled, and logged against climate.
Open data
All of it published. The ocean should be legible to everyone.
Traceable harvest
Every bale traces back to the specific rope in the specific bay.
Research partner
Our lines double as lab infrastructure for universities and institutes.
04
The farm, up close
Shot where the water is cold and the blades are long.
05
One line, underwater
Slow water, swaying blades.
slow water · Stephen Martin
06
Four species
The crop comes in four moods.
the tender one
Winged kelp
Longer blades, firmer bite. A little sweeter at the table.
a. esculenta
the strong one
Oarweed
Thick stipes that shrug off storms. Built for the exposed coast.
l. digitata
the fast one
Sea lettuce
A bright green sprinter that shows up early and everywhere.
ulva lactuca
From the desk of Maren Voss
Most people look at the ocean and see water. I see a farm.
I started kelp with one rope, two buoys, and a borrowed boat. The first winter, the line iced over and I thought we'd lost it all — until spring, when the winch came up heavy with the best sugar kelp I'd ever seen.
What I learned: the ocean doesn't need anything from us. No fertilizer, no feed, no freshwater. Just a rope in the right current, and the patience to let cold water do its work.
So here's the invitation: watch the telemetry, come out on a boat, or just order a bale. The farm is open.
Maren VossFounder, KELP
07
By the numbers
Live, from our backend.
48
longlines deployed
312
wet tonnes a year
6
farm sites
1.9k
t CO₂ removed
08
Loved by the water
People who came out on a boat.
★★★★★
"I've worked on farms my whole life and never seen anything grow this fast with zero input. It's the closest thing to free food the ocean makes."
June P.First-season farmer
★★★★★
"The open data won me over. I can watch the lines grow from my desk, and I know exactly where my bale came from."
Marcus T.Wholesale buyer
★★★★★
"I stood on the deck while the winch brought up a full line of kelp. You can hear it — the whole ocean pulling."
Sofia A.Site visitor
09
The roadmap
Where the farm is heading.
Q3 2026
48 longlines live across six sites, with full telemetry and open data.
Q4 2026
A third coast, plus cold-packing for fresh restaurant supply.
Q1 2027
Kelp bio-stimulants for soil, milled from the whole harvest.
Q2 2027
Community leases — farm a line with us, share the harvest.
10
Questions, answered.
What is kelp, exactly?+
A large brown seaweed that grows in cold, nutrient-rich water. We farm sugar kelp and winged kelp — both edible, both fast-growing.
Does farming it hurt the ocean?+
The opposite. A farm line becomes habitat within a season, and kelp pulls carbon from the water as it grows. No fertilizer, feed, or freshwater is used.
When do you harvest?+
Late spring, once, before the water warms. Timing is set by our sensors, not the calendar.
What is it used for?+
Food, feed, soil bio-stimulants, and research into biopolymers. Most of our harvest is dried and milled.
Is your data really public?+
Yes. Every sensor reading and harvest weight is published in our open data feed. Anyone can query it.
Can I visit a site?+
Boat days open in the spring. Join the waitlist and we'll send the schedule.
The ocean is already farming.
grown underwater.