Ships containing U-21

Sovereign

Spartan

Speedwell

Spence

Spitfire

Splendid

Spot

Spray

Sprig

Spy

St Paul

St. Francis

St. Joseph

St. Nicholas

St. Olaf

Stanley

Star

Starlight

Stars And Stripes

Statira

Steadfast

Steady

Sterling

Stigstad

Stingray

Stork

Storm King

Stranger

Success

Suffolk

Sultana

Sumatra

Summer

Summer Wind

Sun

Sunfish

Sunrise

Sunset

Superior

Suribachi

Surprise

Susquehanna

Svoboda

Swallow

Swan

Swift

Swordfish

Sylvania

Sylvia

Syren

Tally Ho

Tangent

Tara

Tarpon

Tartar

Tasmania

Tasso

Taurus

Teaser

Temptress

Tenacity

Terror

Thalia

Thetis

Thomas

Thorgrim

Thorn

Tiger

Tigress

Tippecanoe

Together

Tom

Toowoomba

Topaz

Torinia

Tortuga

Tracker

Trafalgar

Traveller

Treverbyn

Trident

Trieste

Trinity

Triton

Triumph

True Blue

True Briton

Turtle

Twilight

Two Brothers

U 79

U Never Know

U- 451

U-190

U-21

U-95

U-IT 21

U. S. A.