https://nationalinterest.org/blog/buzz/israel-might-have-300-nuclear-weapons-and-they-are-hidden-ocean-29837
Kohl offered to fully-subsidize the construction of two enlarged Type 209s, designated the Dolphin-class, as well as cover 50 percent of the cost of a third boat in 1994. The Dolphins displaced 1,900-tons while submerged, measured 57-meters long and are manned by a crew of 35—though they can accommodate up to ten special forces personnel. These entered service 1999–2000 as the INS Dolphin, Leviathan and Tekumah (“Revival”).
Each Dolphin came equipped with six regular tubes for firing 533-millimeter DM2A4 heavyweight fiber-optic guided torpedoes and Harpoon anti-ship missiles—as well as four 650-millimeter mega-sized tubes, which are rare in modern submarines. These tubes can be used to deploy naval commandos for reconnaissance and sabotage missions, which have played a major role in Israeli submarine operations.
However, the plus-size torpedo tubes have a useful additional function: they can accommodate especially large submarine-launched cruise missiles (SLCM)—missiles large enough to carry a nuclear warhead. While a ballistic missile arcs into space traveling at many times the speed of sound, cruise missiles fly much slower and skim low over the earth’s surface.