Scullr Online Manual

Thank you for your interest in Scullr GPS rowing computer online manual. This product has undergone extensive testing with a large group of rowers that train with them daily. It has a rich feature set specifically designed for school and club rowing programs. I trust you will be pleasantly surprised by just how helpful these devices are for both rowers and coaches.
Dr. Henry Thomas

1. Overview
2. Charging
3. Use
4. Training Mode
5. Race Mode
6. Castle Mode
7. Ladder Mode
8. Length-Per-Stroke Mode
9. Settings
10. Maintenance

Overview

Operation of the Scullr GPS rowing computer is controlled by two buttons, as well as the accelerometer and Global Positioning System (GPS) receiver. The buttons control the user interface, the accelerometer detects strokes through movement of the boat, and the GPS receiver determines the speeds and distance traveled.

What do the letters beside the numbers mean?

• C = Stroke count.
• D = Distance rowed in meters.
• e = Efficiency measuring velocity variance as an inverse percentage of average boat speed.
• L = Length per stroke in meters.
• R = Rating measured in strokes per minute (SPM).
• r = The prognostic rating derived from boat speed.
• S = Speed
  • 0:00 = 500 meter split time.
  • 0.00 = Meters per second.
• T = Accumulated time or total time rowing (hours, minutes and seconds).

Mount unit securely

It is essential that the Scullr GPS rowing computer is securely mounted to the rowing boat in order to operate properly. Loose mounting may result in an erroneous rating and stroke count, particularly in choppy conditions.

How to change modes

The Scullr GPS rowing computer has five modes: Training, Racing, Castle, Ladder and Length-Per-Stroke. The mode button is used to reset the current mode's counters (except in training mode) or if the counters are already reset, to cycle between the different modes. To change modes press the black Mode Button momentarily one or more times until the desired mode is displayed.

Charging

A USB charging cable is provided with the Scullr GPS rowing computer. When the battery level is low, carefully remove the charging port cover, insert the DC charging connector and plug the other end into a USB power source (0.5 Amp or greater). A red LED above the charging port will illuminate while the unit is recharging. This LED will automatically turn off when charging is complete. It is recommended that you leave the unit plugged in overnight to fully recharge it. When charging is complete remove the DC charging connector and make sure to reinsert the charging port cover.

Important: when you row in salt or brackish water its recommended to lightly rinse the Scullr GPS rowing computer under a fresh water tap and allow it to dry before recharging it. Salt water is damaging to electronic components like the inside of the charging port and the USB charging cable.

Use

The best way to use a Scullr GPS rowing computer is to avoid looking at it constantly. This might seem counter-intuative, but looking at the screen constantly will lead rowers to dip their heads and hunch over at the catch. The best approach is to look at the screen every now an then by glancing at it momentarily at the finish and beginning of the recovery phase when there is negligable impact on a rowers technique.

Training Mode

In Training mode the Scullr GPS rowing computer displays the rating, speed, accumulated time, stroke count and total distance of the current session. The bars on the satellites icon represent the number of GPS satellites detected. When the unit is first turned on, it can take up to 30 seconds for the GPS module to obtain enough satellites for a reliable location fix. The speed and distance letters will flash when there are insufficient satellites. When five or more satellites are available a green LED on the GPS module at the top of the unit will also start flashing.

Odometer

In Training mode, pressing the red Power Button momentarily displays the Odometer Screen, pressing it again returns to the Training mode screen.

Every time the Scullr GPS rowing computer is powered off, if more than 250 meters are rowed, the accumulated training time and distance rowed are added to the session odometer. The Odometer can be reset in the Settings menu.

Race Mode

From the Training mode screen, momentarily press the black Mode Button to display the Race mode screen.

In Race mode the Scullr GPS rowing computer displays the rating, speed, time, and distance. The computer recognizes a race has commenced when 15 or more consecutive strokes are detected at a rating of at least 16 strokes per minute. Prior to the race start, any touch up strokes are ignored. Once underway the race is timed with the distance counting down to zero at the finish line.

In Race mode, pressing the red Power Button momentarily cycles the race distance between 250m, 500m, 1000m, 1500m, 2000m, and 4000m lengths.

Post Race Summary

At the end of a race, when the distance is reached and rowing stops the race summary screen automatically displays. This screen includes the finish time along with a quintile performance breakdown with each segment's stroke rate, speed, length-per-stroke and percentage variance. Pressing the black Mode Button momentarily cancels this screen.

To review previous race results, in Race mode press and hold the black Mode Button until you see the word 'Results' appear across the bottom of the screen. Use the red Power Button and black Mode Button to move forward and backward through previous race records. To return to the Race mode screen, press and hold the black Mode Button until you see the word 'Return' appear across the bottom of the screen.

Castle Mode

From the Race mode screen, momentarily press the black Mode Button to display the Castle mode screen.

In Castle mode the Scullr GPS rowing computer displays the rating, speed, repetitions and duty cycle counter for hard and easy strokes. With each stroke the duty cycle counter increments. When the number of easy strokes are complete the counter is reset and hard strokes are counted. When the number of hard strokes are complete the repitition counter increments and the duty cycle repeats.

In Castle mode, pressing the red Power Button momentarily cycles between 10/20, 20/20, 30/30, 40/40, 50/50 and 60/60 easy vs hard strokes.

Intervals	Race (m)	500	1000	1500	2000
20 / 20	Reps	6	11	17	22
30 / 30	Reps	4	8	11	15
40 / 40	Reps	3	6	9	11
50 / 50	Reps	3	5	7	9
60 / 60	Reps	2	4	6	8

For high intensity interval training use the above table to calculate twice the target race distance. This should be rowed at race pace with alternating light recovery rowing to fully rest rowers between hard sets.

Ladder Mode

From the Castle mode screen, momentarily press the black Mode Button to display the Ladder mode screen.

In Ladder mode the Scullr GPS rowing computer displays the rating, speed, target rating and stroke count. In this mode, the ladder counter steps the rating up and down in four increments, i.e. the 21-30-21 sequence counts 21, 24, 27, 30, 27, 24 and 21 strokes before the sequence repeats. By matching the rating to the stroke count each step takes approximately one minute with an overall time of seven minutes for the sequence.

In Ladder mode, pressing the red Power Button momentarily cycles the ladder counter between 18-24-18, 16-25-16, 22-28-22 and 21-30-21 sets.

Length-Per-Stroke Mode

From the Ladder mode screen, momentarily press the black Mode Button to display the Length-Per-Stroke mode screen.

In Length-Per-stroke mode the Scullr GPS rowing computer displays the rating, length-per-stroke in meters, prognostic rating, speed and efficiency — which measures velocity fluctuations of the boat relative to the water as an inverse percentage of average boat speed.

At any given rating and boat speed efficiency measures how much your technique is disturbing the motion of the boat. Efficiency will tend to decrease as you row faster, and increase as you row slower. The theory is that less disturbance or inertial variance increases efficiency. The formula — calculated during each stroke — is pretty simple:

percent_efficiency = 100 - (100 * (maximum_speed - minimum_speed) / average_speed)

Racing at too high a rating is a common problem with less experienced crews. Obviously developing better rowing technique requires technical coaching and training. Nevertheless using this mode can also help. The prognostic rating simply provides a nominal rating for any given boat speed that can be used as a starting point [6]. Crews row at their target race pace, match the prognostic rating, then adjust their rating to see what effect this has on maintaining boat speed and improving efficiency. When crews find an efficient rhythm at the desired boat speed they can note the length-per-stroke where this occurs. With Length-Per-Stroke finding that rhythm again becomes a lot easier, and over time it becomes second nature.

Settings

To access the Settings screen, from the Length-Per-stroke mode screen press and hold the black Mode Button until you see the word 'Settings' appear across the bottom of the screen.

Press the black Mode Button momentarily to scroll through the different settings and use the red Power Button to change the state of the currently selected setting.

• Meters Per Second when checked, speed is measured in meters-per-second rather than 500 meter split times.
• Daylight Saving when checked, automatic daylight saving time is enabled.
• Time Zone scrolls through time zone offsets in 30 minute increments from Coordinated Universal Time (UTC). For example the timezone here in Bundaberg is +10:00 with daylight saving disabled.
• Zero Odometer is used to reset the odometer at the beginning of a training season.

To return from the Settings screen, press and hold the black Mode Button until you see the word 'Return' appear across the bottom of the screen.

Routine Maintenance

If you row in salt or brackish water its recommended to lightly rinse the Scullr GPS rowing computer under a fresh water tap after every use. If the screen becomes smudged with greasy fingers its recommended to use dish soap to clean the screen by hand, then lightly rinse with fresh water. Do not use a scourer or anything abrasive to clean the screen.

Important! Do not submerge the Scullr GPS rowing computer in water to wash it.

Important! Whenever the screen is covered in salt water crystals avoid wiping the screen with your fingers because salt crystals can scratch the clear polycarbonate cover. Rinse with fresh water instead.

A few times a year dab a cue-tip in petroleum jelly (Vaseline) and wipe the metal surfaces inside charging port with a thin film to protect it from salt water ingress. This was also done when the unit was first manufactured.

Polishing the Screen

If the screen does get scratched or hazy, don't despair it can be polished clear again. This is a quick job, but you will need some supplies.

I have found Silvo silver polish and Meguiars Wet-Look car polish both work well. Other plastic polishes like the Novus System, Meguiars, Mothers, and Autosol Acrylic Polish, may also be a good choice but I haven't tested them. I use Silvo to polish out deeper scratches, and Meguiars Wet-Look to finish up and take out fine scratches.

The process is pretty simple: Using a clean lint free cloth, put a small amount of the polishing compound on the tip of the cloth, apply with moderate pressure in a cross hatch patten. Take your time, don't press harder in an attempt to speed things up, just moderate pressure with rapid side-to-side and back-and-forth movements. After a minute, wipe clean using the body of the cloth and have a look. Repeat by applying polish to a new area of the cloth and keep polishing until the scratches are buffed out. I polish the screens on my rowing computers at the end of every school term.