Watermelon Punch and Bowl

Cut top third off watermelon; trim bottomjust enough to make a flat surface. Scoopout flesh.

Working in batches, pureewatermelon in a food processor. Strainthrough a fine sieve; discard solids.(You should have about 9 cups juice.)Cover rind with plastic wrap. Refrigeratejuice and rind until chilled, about1 hour. Combine juice with seltzer; transfer to rind.