In his 1956 essay "The Frontiers of Criticism" Eliot wrote an apology of sorts for the notes to The Waste Land:
The citation and a fuller quote are available on another page.
I regret having sent so many enquirers off on a wild goose chase after Tarot cards and the Holy Grail.
All that said, the allusion page for the tarot contains links to pages about the various real cards mentioned and a couple not explicitly mentioned in the poem. One of these cards is Two of Wands which, like the Three of Wands in the Rider-Waite Tarot Deck ®, shows a merchant or a wealthy man looking out to sea. The Waite description for the Two of Wands appears to suit the feeling of The Waste Land better than the Three of Wands alluded to by Eliot. Other pictures for the Three of Wands card show a porpoise (Coote). It should be noted that the porpoise also ties in with The Waste Land (they show up at draft for Part IV and in the line 96.
The tarot deck consists of 78 cards, 22 constitute the Major Arcana and the Minor Arcana has four suits of 14 cards each. One suit is known as either rods, wands or staves. The Minor Arcana was only first fully illustrated in 1910 in the Rider-WaiteTarot Deck ® partly named for A.E. Waite who wrote "The Pictorial Key to the Tarot" (1910). Off-hand I would bet that Eliot probably had this deck in mind because it was popular and therefore easy to get a copy of the cards or the Waite book. Also, older cards would not show the man with three staves as that card was not illustrated.
The Rider-Waite Tarot Deck ® is a registered trademark of U.S. Games Systems, Inc. ( http://www.usgamesinc.com/ ).