Large speed display only

[Bowbender]

Tomtom one...Want to display speed only with large size letters on screen. Display speed to a tenth of a mile per hour for bracket boat racing...

 

[canderson]

You would need a 3rd party app designed specifically for this purpose. Device itself has no native ability to produce that kind of display. I'm not aware of a 3rd party that does what you describe, but perhaps someone else will recall one.