David Halpin, 62, had hoped to sail this week on his mercy mission with 17 tons of medical supplies, food and clothing on the Brixham-based beam trawler, the Jacoba.
But the Maritime and Coastguard Agency regulations ruled out the use of the 80 foot (24.2 metre) craft.
After a television appeal, Mr Halpin, who worked at hospitals in Torquay and Exeter, has been offered the use of an ex-Royal Navy tender which is berthed in Bristol.
He made his appeal on the Richard and Judy Show on Channel 4 on Wednesday, where he spoke about his planned £120,000 voyage.
Mr Halpin, from Haytor, Dartmoor, is set within the next week to ferry the supplies on the 6,000-mile round trip, which he is financing.
Mr Halpin said the mission was "a chance to make a difference".
He has been in contact with the Medical Aid for Palestine organisation in London to establish what supplies were needed.
The aid is intended to help the 1.1 million Palestinian refugees from Israel who live in Gaza.
He said: "The children have suffered and about 800 have been killed since in September 2002.
"About half of children are malnourished throughout the occupied territories, and that includes Gaza, which I think is particularly badly affected.
"We hope it is the first of many such voyages."
He has asked the Foreign Office to clear the vessel's entry into the Israeli port of Ashdod, near the northern border of the Gaza Strip.