Learn the “גמרא דף יב. “תנו רבנן לשון ים (three lines from bottom of the Amud) until the two dots on top of דף יב עמוד ב
The Gemara concludes in the case חצר נפרצה לים it is prohibited to draw from the water but permitted to carry inside the Chatzer as long as there are גידודי. Rashi explains גידודי is a wall under the water.
Major Question:
If the wall that is being covered by the water is good enough to allow one to carry inside the Chatzer why does it not also allow one to draw from the water?
Learn תוס’ דף יב: “הכא for many different explanations of the Gemara.
Write out all the different explanations of the gemara answer of גידודי