Empower Oarlock

 The Empower Oarlock provides immediate feedback to assist both rower and coach. View your athletes' technique and output while they're rowing, or as a rower you can make sure you're hitting your targets for technical proficiency and training effectiveness when you need it most: while you're rowing.

Everyone knows that erg power does not always translate to boat speed. Understand WHY and help every rower apply their personal best to the oar. Synchronize crew power application for maximum effectiveness. Combine work measurement with heart rate targets to develop efficiency.

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Provides Immediate Feedback

Assessing your performance after your row requires you to somehow internalize and hold onto suggested changes for your next outing – then try to implement them with no real idea of whether you are doing it right. With real-time technical feedback and effort measurement, you can make sure you're hitting your targets for technical proficiency and training effectiveness when you need it most: while you're rowing.

Quantifies Technique

Rowing faster is a game of increments – "quicker catch", "more compression", "less layback", "longer leg drive". Getting a feel for these subjective concepts on the water can take hundreds of hours. By quantifying catch, finish, and force application into simple numerical targets, technical changes become much easier to achieve and maintain.

Measures Training Effort

Achieving peak fitness requires a "just right" training load, and the EmPower Oarlock takes the guesswork out of determining training effort. By quantifying work, power, and heart rate, you can consistently perform within suggested training zones to maximize physiological training benefits.

Get Immediate Insight

View your athletes' technique and output while they're rowing. Just stay within shouting distance of your athletes to see their real-time technical and effort measurements on a SpeedCoach GPS 2.

So much more than just power

Everyone knows that erg power does not always translate to boat speed. Understand WHY and help every rower apply their personal best to the oar. Synchronize crew power application for maximum effectiveness. Combine work measurement with heart rate targets to develop efficiency.

Set Clear Targets for your Athletes

Supplement your words and drills with measurable targets for each rower's technique and effort.
"Sit up at the catch" becomes "catch at 55°."
"Row half-pressure" becomes "stay within 150-175W."

Go Deeper with Data Review

Review workout data on the SpeedCoach to establish targets and monitor your athletes' performance against them. For even further insight, download the session and export to .csv to analyze and chart per-stroke data in a spreadsheet.



A longer stroke through the water yields a faster boat. Ensure you are hitting target CATCH ANGLES while minimizing SLIP in order to maximize potential boat speed.

Catch timing in team boats is highly dependent on all athletes catching at the same position. Use target CATCH ANGLES to quickly improve timing.





Finishing too short limits potential speed. Finishing too long slows the boat and wastes effort. Finding the proper finish length is tricky business which typically requires years of practice. Quickly optimize the finish with a balance of long FINISH ANGLES and minimal WASH.



Train more effectively by building your training plan around power. With real-time power feedback, you’ll be able to stay in the proper training zone with every stroke to maximize the physiological benefit of your workout.



The Classic mode is structured to always display stroke rate and split, the two key boat performance measures. Two additional flex fields offer the user any of the following metrics:

  • Stroke rate
  • Elapsed Time
  • Current Speed
  • Avg Speed
  • Stroke Count
  • Distance/Stroke
  • Distance/Total


  • Heart Rate
  • Catch Angle
  • Slip
  • Finish Angle
  • Wash
  • Stroke Length
  • Effective Length


  • Power
  • Avg Power
  • Work
  • Avg Work
  • Max Force
  • Max Force Angle
  • Force 


Combine any of these measurements you need for your workout, and have the ability to change them at the press of a button.

Featuring BioRow® Technology


NK's Partnership with BioRow


NK and BioRow PartnershipThe EmPower Oarlock is the result of a collaboration between NK and Valery Kleshnev, founder and director of BioRow. BioRow is a rowing biomechanics research and consultancy firm known for producing both in-depth rowing technique analysis and dozens of medals in international competitions. NK has worked with Dr. Kleshnev since 2014 to merge BioRow approaches to measuring and quantifying complex rowing biomechanics with NK's industry-leading rugged rowing technology and user-friendly SpeedCoach GPS. NK will continue to work with Dr. Kleshnev to take full advantage of BioRow technology, knowledge, and analysis tools as the EmPower Oarlock progresses.


How do we measure force?


The EmPower Oarlock core is a specially designed load cell incorporating multiple strain gauges. The force of the oar during the drive on the face of the oarlock deforms the load cell, generating a strain measurement. This measurement is converted to a Force (Fgate), based on factory calibration values. The Wheatstone Bridge strain gauge configuration helps compensate for temperature variations.

Force at the handle (Fhandle) is calculated using the equation shown, and is a function of the oar length, inboard length, location of force on the handle and location of force on the blade.
Sculling: a=6cm | b=22.5cm
Sweep: a=15cm | b=27.5cm



How do we measure work?

Work is force times distance. In rowing, work per stroke is the average force times the arc length of the oar's travel. We calculate this by integrating work measurements over very short periods of time during the drive. For these short intervals, we multiply the average force times the arc length covered by the oar handle. Work per Stroke is the sum of these work measurements during the drive.


How do we measure power?

Power is work per unit of time. In rowing, power is the Work per Stroke divided by the Time per Stroke. While we use Work per Stroke as calculated on the drive, we use the Time per Stroke for the entire stroke cycle. This is done to account for physiological recovery which occurs during the stroke cycle, whereas the work is done primarily on the drive.


How do we measure angle?

  • 1. The catch is defined as the location where the oar changes direction.

  • 2. Lock occurs when the force reaches 200N for sweep or 100N for sculling. Slip is the difference between Catch and Lock angles.

  • 3. The location of Peak Force is the angle at which the maximum force occurs during any given stroke.

  • 4. Unlock occurs when the force drops below 200N for sweep or 100N for sculling. Wash is the difference between Unlock and Finish angles.

  • 5. The finish is defined as the location where the oar changes direction.

  • 6. An angle of 0° is defined as when the oar handle is perpendicular to the boat. By convention, the oar handle rotated toward the stern is considered a negative angle (typical for the catch), and the oar handle rotated toward the bow is considered a positive angle (typical for the finish).


Display & Pairing

EmPower Oarlock data is displayed on a SpeedCoach GPS 2 with Training Pack. Each oarlock is wirelessly paired with its own SpeedCoach for athlete or coach viewing. Viewing distance is approximately 100’ line of sight from oarlock to SpeedCoach. At launch, the SpeedCoach will support one EmPower Oarlock, and scullers have the option of displaying raw effort-related measurements or doubling them to show total work and power. The SpeedCoach can be simultaneously paired with an NK heart rate belt to aid in developing physiologically efficient rowing.


  • Catch Angle
  • Max Force Angle
  • Finish Angle
  • Force
  • Slip
  • Power
  • Wash
  • Average Power
  • Stroke Length
  • Work per Stroke
  • Effective Length
  • Avg Work per Stroke
  • Max Force 

Connectivity & Software

Wireless connectivity is via Bluetooth® Low Energy. Data download is accomplished using NK LiNK for Windows or Mac OSX and an NK USB Dongle. Selected sessions can be exported from LiNK to an Excel compatible CSV file for viewing per-stroke data. Sessions can also be exported to a .fit file containing boat performance, heart rate and power data that is compatible with 3rd party apps such as Training Peaks and Strava.


EmPower Oarlocks are available for sweep and sculling and use bushings to accommodate various pin sizes. Be sure to order according to your rowing style and boat’s pin diameter. Bushings can be replaced if the oarlock is moved to a boat with different sized pins and if they become worn.

Rowing Style         Sweep           Sculling
Pin Diameters         13mm(blue)
1/2" (white)
9/16" (black)
1/2" (black)
7/16" (white)


The EmPower Oarlock is powered by a single AA battery, easily accessed with a sealed flip-lock door on the back of the oarlock. For most cost-effective use, we recommend rechargeable NiMH batteries such as Panasonic Eneloop® and Eneloop® Pro or Maha Powerex. Rechargeable AA's can be expected to provide 8-20 hours of operation depending on capacity, and multi-packs make it easy to have fresh batteries standing ready to use. For disposable batteries, we recommend Energizer Ultimate Lithium batteries, which will provide roughly double the run time of rechargeable batteries. We do NOT recommend the use of standard alkaline batteries. Particularly if they become damp when stored or installed, alkaline batteries are prone to leaking and the highly corrosive acid will destroy the EmPower Oarlock's electronics. Damage from leaking batteries is not covered under warranty. The oarlock automatically shuts down after 10 minutes without connection to a SpeedCoach.


The EmPower Oarlock is designed and built to be your everyday oarlock. It has a waterproof rating of IP67, which is defined as submersion up to 1m deep for up to 30 minutes. It also passes impact testing according to MIL-STD-810G, Transit Shock, Method 516.5, Procedure IV. This means it can withstand the typical impact you would expect to encounter when carrying a boat in and out of a boathouse. The oarlock can be operated from 32 to 131°F and 5-95% non-condensing humidity. It should be stored in a temperature range of -22 to 140°F.


Installing a brand new EmPower Oarlock typically takes about 10 minutes. We have created a short video series to walk you through the installation steps.
Step 1 - Introduction (3:01 minutes)
Step 2A - Installing on a Standard Pin (3:45 minutes)
Step 2B - Installing on a C-Cup Bracket (2:56 minutes)
Step 3 - Pairing (1:41 minutes)
Step 4 - Configuration (2:40 minutes)
Step 5 - Calibrating your Oarlock (5:03 minutes)



The SpeedCoach GPS is the full-featured rowing performance monitor designed to maximise your training effectiveness. Get detailed insight into your speed, stroke rate and stroke run in any seat of any boat without installing wiring, or add an impeller and pickup for consistent feedback regardless of current. Add the Training Pack option for easily programmed built-in workouts and detailed post-row stroke and split data review, please choose your upgrade option and bumper colour below.

NK LiNK Logbook

A new cloud-based way to view, analyse, store and share your on-water workouts. More than an App, this digital platform provides an innovative way to connect your SpeedCoach GPS, CoxBox GPS, and EmPower Oarlock to a suite of tools to help you get the most out of your workouts. With three different levels of LiNK Logbook, you can select whatever account type fits your needs and budget.