Bud's Potato Salad

Bring a large pot of salted water to a boil. Add potatoes and cook until tender but still firm, about 15 minutes. Drain and allow to cool.
Slice cooled potatoes and layer in a large bowl or dish.
In a saucepan combine water, vinegar and sugar. Bring to a boil and cook for one minute. Remove from heat and pour over potatoes. Cover and chill for at least 12 hours.
Drain excess marinade and add onions, salt, pepper, celery seed and mayonnaise. Mix well and serve chilled.