Fathom Slim ROV Tether (by the meter)

$2.50 / m

This high-performance, low-drag tether is less than 4mm in diameter and has single pair of wires. It’s perfect for travel, deep dives, and long-distance dives. A polyurethane foam jacket makes it rugged and abrasion resistant.

Also see the ROV-Ready version of this product, which comes with a penetrator and connector installed.

This product has a lead time of 1 day to allow for cutting to length.

In stock

Product Price
HS Code: 8544.11.00.30

Product Description

The Fathom Slim Tether is a high performance tether cable designed specifically for ROVs and other subsea applications and optimized for light weight, high strength, and transportability. It is neutrally buoyant, has 300 lb breaking strength, and is embedded with water-blocking fibers to seal any leaks. The tether has a diameter of 4.0mm and is much slimmer than the vast majority of ROV tethers.

The tether carries one unshielded twisted pair (UTP) of 26AWG wire. The core of the cable contains Kevlar strands for strength and Dacron fibers for space filling. Both fibers are impregnated with waterblocking compound to block any leaks caused by nicks or rips in the cable. The high-visibility yellow polyurethane foam jacket resists abrasion and provides neutral buoyancy.

This tether really shines when it comes to it’s size. It’s slim profile makes it ultra low-drag, making it ideal for deep dives, high current dives, and long distance dives where the drag from the tether is really noticeable. The size also makes it incredibly portable and easy to handle. A hundred meter tether weighs just 3 lb (1.4 kg) and can be managed by hand very easily.

Since the tether only has two wires, is can only be used for primary communications with an ROV using Fathom-X Tether Interfaces. There are no spare twisted pairs when using this cable, which means that it is not compatible with the Water Linked Analog Locator and is not ideal for applications where you need extra tether pairs.


Potting a Cable Penetrator

Learn to pot the perfect penetrator to pass a cable into your watertight enclosure!


  • 1 x Slim Tether Cable with bare end (choose length above)


Tether Diameter4.0 mm0.16 in
Weight in Air0.012 kg/m0.00805 lb/ft
Buoyancy in FreshwaterNeutral
Buoyancy in SaltwaterSlightly Positive
Wire Gauge0.14 mm226 AWG
Working Strength35 kgf80 lb
Breaking Strength155 kgf350 lb
Minimum Working Bend Diameter25 mm1 in
Jacket MaterialPolyurethane Foam
DC Resistance @ 20°C0.0445 Ω / ft0.146 Ω / m
Voltage Rating300 VDC

Cross Section

Revision History

3 November 2017

  • R1 – Initial Release


Potting a Cable Penetrator

Learn to pot the perfect penetrator to pass a cable into your watertight enclosure!

Soldering to the Binder 770 Connector

This guide will show you how to solder the Fathom Tether cable and other wires to the Binder 770 Series plug.


Blue Robotics Forum – Product Support