Funding was made available in July 1989 and the contract became effective in January 1990, but in November it was cancelled because of funding pressures in the period leading up to the 1991 Gulf War. The programme was revived with German funding in April 1991, and then in July 1994 Israel exercised its option for a third boat of the same class.

The first steel for the three boats was cut in April 1992, and the boats were laid down in October 1994, April 1995 and December 1996 for completion in July 1999, November 1999 and July 2000 as the Dolphin, Leviathan and Tekuma.

The three boats are similar to the U-212 class except for internal revisions to permit the incorporation of a wet and dry compartment so that underwater swimmers can leave and re-enter the boat. It is also likely that the boats are fitted with the Triten anti-helicopter SAM system.

Primary anti-ship and anti-submarine armament is the STN Atlas DM2A4 Seehecht wire-guided torpedo carrying a 260-kg (573-lb) warhead to a range of 13 000 m (14,215 yards) in active mode at 35 kts, or to 28 000 m (30,620 yards) in passive mode at 23 kts. Pending the delivery of the complete DM2A4 package from Germany, a number of NT37E torpedoes are included in the torpedo fit. Tube-laid mines are an alternative to the 16 torpedoes, and other weapons that can also be launched are up to five UGM-84C Sub-Harpoon underwater-launched AShMs, or conventionally armed cruise missiles of Israeli design and manufacture. In addition to the six 533-mm (21-in) conventional tubes, the boats also have four 650-mm (25.6-in tubes optimized for the launch of swimmer delivery vehicles (SDVs) but with provision for the carriage of liners so that they can also be used as conventional torpedo tubes.

The boats are painted in blue and green for reduced visibility in the shallow water of the East Mediterranean.