Both-to-Blame Collision Clause is a BIMCO clause:
"If the Vessel comes into collision with another ship as a result of the negligence of the other ship and any act, neglect or default of the Master, Mariner, Pilot or the servants of the Carrier in the navigation or in the management of the Vessel, the owners of the cargo carried hereunder will indemnify the Carrier against all loss or liability to the other or non- carrying ship or her Owners in so far as such loss or liability represents loss of, or damage to, or any claim whatsoever of the owners of said cargo, paid or payable by the other or non-carrying ship or her Owners to the owners of said cargo and set-off, recouped or recovered by the other or non-carrying ship or her Owners as part of their claim against the carrying Vessel or Carrier. The foregoing provisions shall also apply where the Owners, operators or those in charge of any ship or ships or objects other than, or in addition to, the colliding ships or objects are at fault in respect of a collision or contact."
" Both to blame clause forms part of some bills of lading and refers to who was at fault and responsible for payments if two vessels collided while one was carrying cargo pursuant to a bill of lading. Generally, when two vessels collide, they become liable to each other proportionately for the total damage. The vessel with the lesser damage may impose upon the cargo being carried to contribute to the amount to be paid to the other vessel. The “Both to Blame Clause” in the cargo policy provides that in such event, the cargo policy will cover such contribution. In other words, upon the collision of two or more ships, when all ships are at fault, all owners and shippers having monetary interests in the voyage of the ships involved must share in all losses in proportion to the monetary values of their interests prior to the occurrence of the collision. The Both to Blame Clause supersedes all other provisions for the allocation of losses among owners and shippers in ocean marine policies."