An ocean of determination ... the call to prayer on the MV Blue Marmara.Credit:Kate Geraghty
But the banners and the bugle calls,the prayer meetings and talk sessions are all about the Israeli blockade of the Gaza Strip and the rights of its 1.5 million people who,the shipboard activists say,are punished collectively by Israel because they support Hamas - which Israel,the US and Europe have declared to be a terrorist organisation.
Organised by IHH,a Turkish rights group headed by the taciturn Mr Yildirim,the big seagoing ferry is carrying 350 Turkish protesters and 250 more from 50 other countries. They include 35 members of various parliaments around the world.
Last night,the MV Blue Marmara was expected to lead the first wave of a flotilla of protest vessels assembling south of Cyprus to sail towards Gaza,to challenge Israel's lock on the impoverished enclave.
Israel,which says it will seize the flotilla's four cargo boats and carry out security checks before it delivers supplies to Gaza,has warned that the 700 activists on the ships will be required to make a snap decision:be deported or jailed.
Masked navy commandos are expected to board the ships,to commandeer those whose captains refuse to alter course away from Gaza. All the activists on board the ships have been given rudimentary training in non-violent resistance.
Israeli forces last week carried out manoeuvres,practising detaining the ships and all on board. Asked in the face of this dry run if he figured he was going all the way to Gaza,Mr Yildirim said:"Yes. I believe I am."
The prospect of his chartered Turkish ferry and two Turkish cargo ships spearheading such an audacious challenge to Israel by a global coalition of Palestinian support groups is a measure of the recent collapse in relations between Jerusalem and Ankara,once a vital,reliable ally of Israel.