Can you ride jet skis in GTA 6?

Yes. Game Informer confirms jet skiing, and two jet skis appear in the Extended Look.

Are there jet ski races in GTA 6?

Not confirmed. GTABase lists sea races, as in GTA V, but none has been shown.

Game Informer's cover story confirms jet skiing, along with street and off-road racing and airboating.
The Extended Look shows two jet skis carving across Vice City waters at sunset, the skyline ahead.

Press previewSeen in gameplaySources 1 2 3

01 / Activities
GTA 6 activities
29 GTA 6 activities confirmed: robberies, street races, gym, hunting, fishing, scuba, mini golf, pool, nightclubs. Plus 8 seen or probable.
02 / Activities
GTA 6 kayaking
Kayaking is a confirmed GTA 6 activity, per Game Informer. Lucia paddles across a Vice City marina, and a Crest Kayak waits outside Jason's safehouse.
03 / Activities
GTA 6 airboating
Airboating is a confirmed GTA 6 activity, per Game Informer, and Rockstar's own Grassrivers screenshot shows an airboat crossing the swamp.
04 / Activities
GTA 6 scuba diving
Scuba diving and snorkeling are confirmed in GTA 6, per Game Informer. You dive with an oxygen meter, and the Extended Look shows an underwater cave.
05 / Activities
GTA 6 street races
GTA 6 street races take up to 16 racers on laps or point to point, with pink checkpoints and nitrous in some. Off-road racing is confirmed too.
06 / Guide
Leonida Keys on the GTA 6 map

Still unknown: Where to rent or find jet skis, and whether there are jet ski races.

Can you ride jet skis in GTA 6?
Yes. Game Informer confirms jet skiing, and two jet skis appear in the Extended Look.
Are there jet ski races in GTA 6?
Not confirmed. GTABase lists sea races, as in GTA V, but none has been shown.