When the pool fence is not in place, there should be a sturdy cover over the pool to prevent anyone from falling in. Normal pool covers are not designed to support the weight of a person, and are therefore not sufficient.
Generally speaking, pool safety fencing costs $15 to $20 per linear foot. For removable fencing, the cost of a pool safety cover should also be factored in. They can cost from $400 to over $1,200 depending on the size and material of the cover.
Costs vary greatly by region (and even by zip code). To get free estimates from local contractors, please indicate yours.