Answer:
No, since it being merely a gratuitous promise
Step-by-step explanation:
The word "gratuitous" refers to something that costs nothing i.e free of cost.
A gratuitous promise refers to a promise made by one party to another to perform an act, the performance of which accrues to the benefit of the other party, wherein no consideration for performance of such an act is received.
In the given case, John made a gratuitous promise of insuring the ship to prevent any loss or damage. John failed to perform the promised act and the ship met with a sea calamity leading to wreckage and loss. Co-owners sued John against non performance.
In the given scenario, the co owners will not succeed as John wasn't bound by any contractual obligation. It was merely a gratuitous promise at his end and he was under no obligation to insure the ship as he received no consideration against his promise.