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Spar, Dock, Walkway, and Water Patio (Shallow Water Model)

Base Structure of The Shallow Water Model (aka The TriSpar)

This is the base structure of the shallow water trispar model (March 27, 2021 model PDF, .STP).

The central and outer spars are made of steel. The outriggers are made of steel and filled with air. The outer spars are partially filled with cement.




Using online triangle calculator. Footprint = 12m (outriggers) + 1m (side spars) + 0.81m (1.62/2 center spar) - 0.050m (inside center spar overlap) - 0.03m side spar overlap = RADIUS of 13.73 (12+1+.81-.05-.03).

Perimeter: 71m

Outer Spar to Outer Spar: 23.6m

Area: 244m2

Circumference Radius: 13.73m

Incircle Radius: 6.8

Minimum Width: 6.865+13.73= 20.595m

Volumn of Submerged Areas
Total submerged area: 47.8 m³

Steel only: 5.2 m³ (41,714 kg)

Steel only (underwater sections): 4.6 m³ (37134 kg)



Spar Door

You can choose between a steel door, a fiberglass door, and a transparent door with fiberglass frame. An NFC reader to unlock your door as well as smart locks will be available with the Smart Home Upgrade Package. The door is water tight against splashes and waves but it not meant to be submerged for long periods.



Underwater Access

Certain section of the TriSpar is big enough to crawl through in case you need to. There may be storage tanks in these areas.

Hatch to underwater section of the TriSpar

We will have a circular watertight hatch under the spiral staircase to enter the underwater section of the spar. The hatch will have an opening of 600-700mm and be similar to this.


Here is a rough layout showing the position of the hatch relative to the stairs at the entrance. The hatch will be between 600-650mm width.


Spiral Staircase

There is a spiral staircase that starts just above the waterline and goes up to the living room. We will have a default stair step design and upgrade options to have a custom design. Some custom designs are shown below.


Dock Area

There is a 4.8m diameter dock built around the base entrance of the SeaPod. The dock surface is 1.5m width and circles the center spar which is approximately 1.620m width. The renders below give you an idea of what this area will look like but there will not be a fence around the dock and there will be a walkway to one of the outer spars. The dock is made of a gray color fiberglass grating (like this or this local supplier).


The Dock grating squares will be a gray shade similar to the below sample


Idea for a Paddleboard Stand


Mooring Cleat

Option, same supplier we are using for other components in the Pod

Screen Shot 2021-03-13Cleat.png

Boat Winch (Upgrade)

Option. We are using this same supplier for other parts.

Inflatable Life Raft

Best Option. Non-self inflating option from same supplier we are using for other parts. Inflatible Raft with electric motor

Anchor Lights

We will have one light on each outer spar. Source or here.


There will be up to 3 concrete weights as anchors on shallow water SeaPods. Future SeaPods that are able to move under their own power may use Rocna 40kg as anchors. Backup supplier can be other type options (we are getting a lot of supplies from this source).

Steel Hull

The steel hull is made from AH32 steel at 15mm for the central spar and the outriggers and outer spars are 12mm. The steel is protected from rusting with a light gray color zinc coating. Optional white paint top coating is available. We are also using Active Cathodic Protection of the spar (3VDC @ 2-6amps) to protect from rusting corrosion.

Sensors, Switches, Controls, and Motors

There will be multiple sensors inside the spar and in the water as part of the smart home upgrade kit. The fire related sensors come standard on all Pods.

  • Flame Detector (standard)
  • Smoke/Gas detector (standard)
  • Heat Dectector for fire (standard)
  • Magnetic Door Lock or other IoT locking mechanism (Smart Home Upgrade Package)
  • Humidity (Smart Home Upgrade Package)
  • Movement sensor (Smart Home Upgrade Package)
  • Air Temperature (Smart Home Upgrade Package)
  • Floor Sensor (standard)
  • Bildge Pump (standard) - Approximately 1,500 GPH capacity
  • Voice Assistant Mic (Optional with a manual master hardware switch) (Smart Home Upgrade)
  • Camera for security (inside and outside) (Smart Home Upgrade Package)
  • NFC reader on door to unlock door (Smart Home Upgrade Package)
  • Spar Electrification to protect steel from rusting
  • Dissolved oxygen sensor (OoT Upgrade Package)
  • Turbidity Sensor (OoT Upgrade Package)
  • Salinity Sensor (OoT Upgrade Package)
  • Conductivity Sensor (OoT Upgrade Package)
  • pH Sensor (OoT Upgrade Package)
  • Water Temperature Sensor (OoT Upgrade Package)


Each SeaPod can have up to 3 walkways that extend from the center spar to the outer spar.


For the walkway we are considering edging that can be used to make a round dock or a wavy straight walkway. A single piece is shown below:


Each edging can have a hole added so that accessories can be added like a handrail, ladder, light plugs, mooring cleats, or other accessories.






Water Patio (Wazebo) and other Add-On Modules

The outer spars of a SeaPod can be left plain and unfinished or they can be upgraded with solar stations, gardens, wazebo's (over-the-water gazebo's) or additional living areas. The Wazebo has a diameter of 6.8m (22.8 feet) and gives you an additional 390.9 square feet of livable space.

Solar Station

Each SeaPod can have up to 3 solar stations located on the outer spars of their pods frame. Each station is 4.8-6.8m in diameter. These are the solar panels (450w or 550w) we will use.

Ballast Tanks 

There are 3 ballast tanks that will be located inside each of the outer spars. Each tank can hold up to 1.6m3  (422.72 US Gallons) of water or 1,600kg of ballast. Each tank will be automatic and independent controlled to keep the Seapod stable at sea.