CSS

animate a position css

#wrapper{
    position:relative;
    top:50px;
    width:700px;
    height:320px;
    margin:0 auto;
    background:white;
    border-radius:10px;
}
#sea{
    position:relative;
    background:#2875DE;
    width:700px;
    height:170px;
    border-radius:10px;
    top:190px;
}
#sea img{
    position:absolute;
    left:480px;
    top:-20px;
    animation:myship 10s;
    -moz-animation:myship 10s; /* Firefox */
    -webkit-animation:myship 10s; /* Safari and Chrome */               
}

@keyframes myship{
    from {left: 480px;} 
    to{left:20px;} 
}
@-moz-keyframes myship{
    from {left: 480px;} 
    to{left:20px;} 
}
@-webkit-keyframes myship{
    from {left: 480px;} 
    to{left:20px;} 
}​