A web map and Collector for ArcGIS requires that a basemap is in place. It is possibe to create your own basemap using one of these methods: Using tile packages for publishing hosted tile layers | ArcGIS Blog
In your case you would create a polygon for your area of interest that has no fill or outline and share as a tile package.
Basemaps are there to provide context for end users, will the data be usable with no visial guide of where they are?
Thank you so much for your quick response. The data would still be accurate if pulled into a basemap after the fact correct? If we collect it without a basemap that would be to speed up the collection process/counter the crashes well logging positions that the current version of Collector currently is facing. My area of concern would be that in the end would we be able to remove the tile layer and use a different basemap?
Once again thank you for the help!
As long as coordinate systems were kept aligned, the data would still be accurate (depending on the GPS of the device etc.) and the layer can be add to another basemap.