不可转让海运单（Non-negotiable sea waybill）是指在海洋运输方式下，由承运人或其代理人接受托运人委托，对其签发的货运单据。不可转让海运单是海上运输合同的证明和货物收据，它不是物权凭证，不能背书转让。收货人提货时无须出示海运单，承运人仅凭收货人提交的证明其为海运单上指定收货人的凭条交付货物。如果信用证没有表示可接受此类单据时，银行就不能接受。

如：

1.This provision applies even when loading on board or shipment on a named vessel is indicated by pre-printed wording on the non-negotiable sea waybill. 

即使非转让海运单上已注明印就的“已装船”或“已装具名船只”措词，本规定仍然适用。

2.This provision applies even when loading on board or shipment on a named vessel is indicated by pre-printed wording on the non-negotiable sea waybill. 

即使不可转让海运单以预先印就的文字表明货物已由具名船只装载或装运，本规定也适用。

3.The sea waybill is a non-negotiable receipt for the goods loaded aboard the carrying vessel at the port of loading, which also evidences the terms and conditions of the contract of carriage. They are not negotiable documents, nor documents of title.The sea waybill is described in the U.K.’s Carriage of Goods by Sea Act 1992 as “any document which is not a bill of lading but (a) is such a receipt for goods as contains or evidences a contract for the carriage of goods by sea; and (b) identifies the person to whom delivery of the goods is to be made by the carrier in accordance with that contract.”. 

海运单是在装货港装船货物的不可转让收据，也是运输合同条款的凭证。它们不是可转让单证，也不是所有权凭证。海运提单在1992年英国《海上货物运输法》中被描述为“不是提单的任何单据，但（a）是货物的收据，包含或证明海上货物运输合同；以及（b）指明承运人根据该合同向其交付货物的人”。