This works well on boats of all sizes that don’t have an oven.
2 t sugar
1-1/2 t salt
1 T yeast
1-1/2 C water
2 C white flour
2 C whole wheat flour
2 T oil
Dissolve sugar, salt, and yeast in water. Let stand 5 min. Blend in flour and knead well. Allow to rise until volume doubles. Punch down and knead again. Grease dutch oven or pressure cooker and dust with flour. Cover and then cook for 45 minutes over very, very low flame. Do not open and look! To brown the top, turn over and cook for 10 minutes.
When we tried this using high-gluten white bread flour, instead of whole wheat, it only needed 35-40 minutes of cooking. But be warned — it’s hard to get the flame low enough, even with a flame tamer, so the bottom may be a little overdone.