Abdullah bin Umar (may Allah be pleased with them both) narrates: The Prophet (peace and blessings be upon him) was asked about performing prayer on a boat, so he said: "It should be performed standing, except if you fear drowning (then the ruling is different)."
Hadith Referenceسنن الدارقطني / كتاب الصلاة / 1474
Hadith Takhrij«أخرجه الحاكم فى ((مستدركه)) برقم: 1024، والدارقطني فى ((سننه)) برقم: 1474، والبيهقي فى((سننه الكبير)) برقم: 5573، 5574»