Gave my Sunfishes a blow job. Only got a few bubbles.....

I have a larger sized hand pump used to inflate inflatable matresses. You hold the base with your foot and pump. It moves a lot of air at low pressure. I find you can adapt the end to fit various drains on the sunfish. I picked up the pump at a garage sale for dollar or so. Them might also be found at thrift shops. We like keeping the costs down when we can!
FWIW, I have an air compressor that can make a lot of air. Sometimes the better tool is a simple hand tool. I figure it will be much...

Gave my Sunfishes a blow job. Only got a few bubbles.....