Overview
DAVE THE DIVER has no native ultrawide support on 21:9 or 32:9 monitors; the entire game (both the diving segments and the restaurant management view) runs pillarboxed at 16:9 with black bars on both sides at all times. The only widely-discussed workaround is a generic borderless-window tool that removes the bars by stretching the fixed view rather than properly extending the playable area, so it is a cosmetic fix at best.
Compatibility details
Fixes
The game has no native ultrawide support at all (PCGamingWiki lists ultrawidescreen=false, pillarboxed 16:9). The only workaround found is forcing a borderless window with a third-party tool (Borderless Gaming), which removes the black bars by stretching/cropping the fixed 16:9 render rather than genuinely extending the field of view, so it is not being recommended as a clean fix.
