Breath of the Whale

You touch a willing creature it gains a whale sized lung capacity of air it can hold in its chest for up to 90 minutes.  You can use the magical air to speak or cast spells while underwater, reducing the duration by 10 min each turn spent speaking and/or casting.

While under the effect of this spell you can exhale a whale sized capacity of air and make the long, low-frequency sounds known as the whale song.

For each slot cast above 2nd level, you can target an additional creature.