Boat EconomicsStorage, Maintenance, Insurance, and Reserve
What Does Saltwater Exposure Actually Add to the Bill?
Blend your own service and reserve assumptions by saltwater exposure share to see the modeled annual and five-year cost delta against a freshwater baseline.
"Saltwater costs more" is a real pattern, not a fixed number
Saltwater exposure genuinely tends to raise flushing, inspection, and corrosion-related repair costs, but by how much depends on your specific boat, equipment, flushing discipline, and region. Rather than asserting a generic dollar figure, this engine scales the premiums you enter, informed by your own mechanic or experience, by your actual exposure share.
How this is calculated
The freshwater baseline sums your annual scheduled service and reserve. The saltwater premium (extra service, extra reserve, trailer corrosion premium, and extra haul-outs) is scaled by your saltwater exposure share and added on top, along with any prevention spend you enter directly. The five-year delta is simply the annual delta multiplied by five, a straight-line projection rather than a compounding one.
Worked example
A freshwater baseline of $600 service and $400 reserve totals $1,000 a year. At 100% saltwater exposure with a $300 service premium and $300 reserve premium, the scenario totals $1,600 a year, a $600 annual delta and $3,000 over five years. At 50% exposure, that delta halves to $300 a year, since the premiums scale linearly with exposure share.
Common mistakes
Treating a generic "saltwater costs X more" figure as universal ignores real variation in equipment and care; use your own mechanic's quotes or documented experience for the premium fields instead. The other mistake is forgetting trailer and frame corrosion when the boat is trailered through saltwater launches even if stored on freshwater.
Frequently asked questions
Does saltwater always cost more to own in?
Not by a fixed, universal amount. Corrosion outcomes depend heavily on equipment, flushing routine, care, and local conditions. This tool does not claim a defined dollar loss for saltwater; it scales the extra service and reserve premiums you enter by your own exposure share.
What if I split time between fresh and saltwater?
Set the saltwater share to the percentage of your use that is in saltwater. The tool blends the freshwater baseline and saltwater premium linearly by that share, rather than treating it as all-or-nothing.
Does prevention spend (zincs, coatings) actually help?
This tool does not model prevention as reducing the premium automatically. Enter your own prevention spend as its own line item; if you believe good prevention lowers your service or reserve premium, adjust those figures down yourself based on your own experience or a mechanic's input.
How is this different from Annual Boat Maintenance Reserve?
That engine estimates a reserve for your specific boat regardless of water type. This one isolates the incremental cost attributable to saltwater exposure specifically, against a freshwater baseline you define.