Residents were woken up at 4am on Saturday by a jetski roaring up and down the coast.
People living along Goring seafront in Worthing have now called on the borough council to crack down on the dawn riders.
But a council spokes-man admitted: "There is nothing we can do."
On calm days jetskiers from all over the South-East launch their craft from the Alinora boat ramp.
The noise, similar to that made by motorbikes, travels up to a mile inland.
Richard Waller, chairman of Goring Residents' Association, said: "Not many residents like the jetskis anyway - and 4am is definitely not on."
He urged people to take the car registration of the culprits and complain to the council if it happened again.
But the council said its hands were tied.
Following concerns about reckless jetski riding, it asked the Government to introduce a licensing scheme but Whitehall refused.
Bylaws exist but they do not cover the time jetskiers can take to the water.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article