Learn how to play Dive Master here.
A few basic pointers: Each player holds 7 cards in hand at each turn. When it's their turn, they pick one card from the face down deck OR the discard pile and play their card in front of them on the table (so, pick one & play one). Arrange your cards like a train going down for descent cards and going up for ascent cards. Remember, you can use a Start Descent and Start Ascent cards as a -1 and +1 correspondingly.