The Marker Guardian S4000SMN is a multi-purpose buoy that can be adapted to perform a range of tasks limited only by the costumers needs. S4000N has a large volume which allows it to be equipped with a considerable amount of batteries, and a large surface that can support the installation of solar panels. The excellent buoyancy allows install wind turbines which adds more energy independence and less maintenance operations. This energy can be then used to recharge UAV’s operating nearby or maintain surveillance operations of ports entries, feed water quality monitoring devices, etc.

Water quality monitoring devices can be easily installed and readings can be taken either dependent or independently. Probes will function accurately and reliably in fresh, salt or brackish water.

S4000N and can be upgraded with up to 32 sensors, communication antennas, all protected inside the structure without loss of efficiency. Its’ simplified modular structure and electronics allows for easy upgradability and maintenance. Devices can be installed to meet specific client needs, from low cost energy efficient sensors to high precision instruments devices can be installed to meet specific client needs.

This Guardian can generate alerts and send them to mobile devices via Wi-Fi or Bluetooth. For monitoring of several devices radio frequency transmitter is used connecting many devices to 1 central server. This allows for a real time monitoring of multiple parameters, such as: dissolved oxygen, salinity, water level, temperature, pressure, position or live video.

The MG S4000SMN is fully built in composite, withstanding impacts, solar exposure, salt water and corrosion exemplary. Each section is laminated using UV-stabilized, isophthalic polyester resin reinforced with Kevlar* and glass fibers to obtain maximum durability, crash resistance and water impermeability. With thicknesses ranging from 10 up to 15mm this structure is rigid durable and reliable.

The fully composite structure assures a rust free, low maintenance lifespan. No part of the structure requires painting at any stage of the product’s life span. The MG can be supplied in all I.A.L.A. colors.


Consult Specifications tab for detailed information.


Isophthalic NPG Polyester resin reinforced with Kevlar and glass fiber; 316-grade SS fixtures.

Mass (Kg | lb)

2631 | 5800

Volume (L | gal)

7673 | 2027

Reserve Buoyancy (Kg | lb)

6723 | 14820

Nominal Draft (mm | in)

675 | 26,6

Draft, Maximum (mm | in)

576 | 22,7

Nominal Freeboard (mm | in)

1520 | 60

Freeboard, Minimum (mm | in)

300 | 11,8

H max (mm | in)

6054 | 238,3

Focal Plane Height (mm | in)

3360 | 132,3

Total Float Volume (L | gal)

20641 | 5453

Maximun Mooring Load (Kg | lb)

2017 | 4446

Safe Working Load, 1pt (Kg | lb)

10000 | 22046

Submergence  (Kg/cm | lb/in)

9,96 | 21,96

Visual Area (m2 | ft2) (no signs)

7,5 | 80,7

Water Area (m| ft2)

14 | 150,7

Wall Thickness (mm | in)

7 | 0,28

Ballast (Kg | lb)

1680 | 3704

Height (mm | in)

6054 | 238,3

Width (mm | in)

4000 | 157,5

Available Colours

Yellow, Red and Green as per I.A.L.A. recommendations

Product Life Expectancy (years)


Intellectual Property Trademarks

Water Guardian and Marker Guardian are a registered trademark of Composite Solutions, Lda..

Quality Assurance

ISO 9001:2008

Warranty (years)


Standard Equipment

Data logger with Bluetooth connectivity with upgradability up to 32 sensors

32Gb of data storage

LCD display

Adjustable measuring time intervals.

Optional Equipment

Temperature, humidity, wind & pressure Kit

Electrical conductivity, temperature & depth sensor Kit

Wi-Fi, VHF, Iridium, RF, GPRS, 3G & 4G


Dissolved Oxygen Kit

Wi-Fi, VHF, Iridium, RF, GPRS, 3G & 4G

Surveillance camera/motion sensor Kit

Solar Panels

Upgraded battery capacity

Status light