Everyone quotes in dollars per linear foot because length is the one thing measurable from the driveway. It is also the variable that explains the least about why two quotes differ.
A per-linear-foot rate is a price divided by a length. It looks like a unit cost and it behaves like one only if the thing being priced is the same in both cases. For seawalls it almost never is, which is why the published Florida rates disagree by roughly 8x while all describing something called seawall replacement.
This page is about what the unit conceals. Not to argue that the rate is useless — it is how the industry works and you will be quoted in it — but because a homeowner who understands what is inside and outside the number asks materially better questions than one comparing two figures.
Repair spans $25 to $600 per foot — a 24x spread within a single category, driven almost entirely by whether the top of that range includes full panel and tieback replacement. That is the whole problem with the unit in one line: the same number describes sealing a joint and rebuilding the structural system.
None of these are dishonest exclusions. They become a problem only when they are excluded silently and reappear later as a change order.
Getting equipment, a barge or a pile driver to the site is a fixed cost that does not scale with length. Spread across 60 feet it is a large share of the rate; across 200 feet it nearly disappears. Two neighbours quoted the same per-foot rate are not being offered the same deal.
Removing the failed wall and disposing of marine debris is a separate operation, charged separately by most contractors, and absent from most published rates.
Whether new tiebacks or helical anchors are included is the single largest structural variable hiding inside a per-foot number, and it is invisible in the finished wall.
Volume nobody has measured. A rate cannot include an unknown quantity, so either it is excluded or an assumption has been made that you should see.
Published Florida permit figures run $500–$2,000 generally and $1,500–$6,000 in South Florida. Engineered design is required outright in some jurisdictions.
Removal, working around, and reinstatement. Frequently the difference between two otherwise identical quotes.
Anchor installation disturbs the yard. Whether grass, irrigation, paving and landscaping get put back — and to what standard — is rarely in a per-foot rate.
A neighbour with 200 feet of wall pays a rate. You have 70 feet. If the fixed component of the job — mobilisation, permitting, engineering, site setup — is the same for both of you, then your rate is higher for reasons that have nothing to do with anyone taking advantage of you. Length divides the fixed cost; it does not reduce it.
This works in the other direction too. A very low rate on a short run is worth a question, because either the fixed costs are not in it or something has been left out. The range tool shows what every published rate produces at a length you enter, which makes the width of the honest answer visible before anyone quotes you a point inside it.
Ask both contractors to price the same seven things rather than the same length: demolition and disposal, anchors, void filling, permitting and engineering, dock and hardscape handling, upland reinstatement, and how much adjacent wall is included. Whichever quote changes when you ask is the one that was not comparing like with like.
The full driver list is on the replacement cost page, and the reasons the published figures conflict in the first place are on the cost evidence page. If you have not yet established whether you are in the repair band or the replacement band, that is decided by the failure mechanism — start with the failure library.
No single number, and no form in front of it.
What moves the number besides length.
Including a publisher contradicting itself.
What to verify before signing anything.