'Ramming the U-boat' refers to the act of DP of a young lady with two gentleman's parts in the same nether orifice - whether that be Dv or DA. Once one gentleman's part has been inserted, the second gentleman can be said to be 'ramming the U-boat' as he introduces his equipment alongside the first gentleman's parts - a process which will necessitate two two penii contacting each other repeatedly. The adult actress Gauge can often be seen in her films as the hostess to such an action.
While the act of 'ramming the U-boat' does involve penis-to-penis contact between two men, it's widely accepted to be only gay if the balls touch.
A person obsessed with their very very U-Boat personality and can act very viciously if their identity is stripped away from them. U-Boats love to make love with flowers.