Most real estate math treats purchase price and monthly carrying cost as two separate decisions. You negotiate the price, then you separately budget for taxes, insurance, and in Sausalito's floating home community, a berth lease paid to the marina. On land, those numbers rarely talk to each other. On the docks at Richardson Bay, as of this year, they do.
A new state law that took effect January 1, 2026, gives some Sausalito marina owners the right to reset a floating home's monthly rent at the time of sale, and the ceiling on that reset is calculated directly from the price the buyer agreed to pay. Overpay for the house, and you may be signing up for a higher rent ceiling along with it. Underpay, and the math can work in your favor for years. Nobody selling you a berth-side view is going to walk you through that arithmetic before you write an offer, so here it is.
The Formula Behind the Coupling
The law is Assembly Bill 754, authored by Assemblymember Damon Connolly and signed by Governor Newsom on October 10, 2025. It rewrites California's Floating Home Residency Law specifically for Marin County, the jurisdiction that holds the vast majority of the Bay Area's roughly 425 floating homes, compared with a much smaller number in Alameda and Contra Costa counties.
The provision that matters most to buyers is what the bill calls an "in-place transfer." When a floating home with a qualifying 10-year-or-longer lease changes hands, and the marina offers the incoming owner a lease of similar length, the marina is allowed to reset the berth rent. But not by any amount it chooses. The increase is capped at whichever is lower: 25 percent above the prior rent, or 0.15 percent of the certified sale price. The buyer has to certify that sale price in writing, under penalty of perjury, so the number driving the formula is the real one.
Run that 0.15 percent figure across a range of prices and you can see how directly it scales with what a buyer agrees to pay:
| Certified Sale Price | 0.15% Monthly Rent Ceiling |
|---|---|
| $700,000 | $1,050 |
| $1,500,000 | $2,250 |
| $2,500,000 | $3,750 |
Those numbers are not what any specific dock will charge. They are the mathematical ceiling that price alone generates. Whether that ceiling actually binds, or whether the 25 percent cap kicks in first, depends on what the outgoing owner was already paying, which is the part most buyers never think to ask about until it is too late to negotiate.
What Happens When Rent and Price Are Fully Decoupled
To understand why Marin lawmakers built a price-linked formula at all, it helps to know what came before it. In 2022, Assembly Bill 252 imposed rent and vacancy control on floating home marinas across Alameda, Contra Costa, and Marin counties. It capped annual increases at 3 percent plus the change in cost of living, or 5 percent, whichever was lower, and it barred marinas from raising rent at all when a home sold.
That full vacancy control sounded like a clean win for residents, but Marin's marina owners argued it stripped away the one mechanism they had relied on to fund seawalls, dock repairs, and the kind of capital work that keeps a floating home community above water, literally, as sea levels rise. According to the Marin County Board of Supervisors' own account of the negotiations that followed, some marinas responded by shifting away from long-term leases entirely, moving tenants onto one-year terms and introducing new fees to recoup revenue they could no longer collect through rent at the point of sale.
Yellow Ferry Harbor's harbormaster at the time, Chris Tellis, captured the marina owners' frustration bluntly.
"No one has ever heard of rent control in the richest county in America."
That tension is what sent the Floating Homes Association's Legislative Action Committee and Marin's marina owners into more than two years of direct negotiation, culminating in the compromise that became AB 754. The bill passed the Assembly and Senate without a single "No" vote, and a resident survey conducted before the final language was set showed 93 percent support among more than 400 respondents across a 67 percent response rate. Even a Republican state senator who had never backed rent control before signed on, telling colleagues in committee that with everybody agreeing, it was hard to say no.
Doing the Math on Your Own Dock
The 0.15 percent price formula only matters where it is the lower of the two caps. Below a certain sale price relative to the prior rent, price is the binding constraint and negotiating the number down genuinely protects your future rent. Above that threshold, the 25 percent cap takes over and the sale price stops mattering to the formula entirely.
Here is how to find that crossover point for any specific home. Take the prior monthly rent and multiply it by roughly 833. That is the sale price at which the two caps converge. Below that price, the 0.15 percent formula governs. Above it, the 25 percent cap does.
As one point of reference, Tellis put Yellow Ferry Harbor's average berth fee at around $1,500 a month back in 2022, when the earlier law was being debated. Multiply that by 833 and you get a crossover point near $1.25 million. Under AB 754's cost-of-living floor of at least 3 percent annually, that 2022 figure has almost certainly climbed since then, so the actual crossover point on any given dock today will sit higher. The exercise is the same regardless of the exact number: ask the marina or the listing agent for the current rent on the specific berth, run the multiplication yourself, and you will know whether your offer price is a lever worth pulling or a number the rent formula will ignore anyway.
The Fine Print That Changes by Dock
A few details narrow how often this actually applies. The vacancy decontrol only fires if the outgoing owner's lease already ran 10 years or longer, or was offered one, and the incoming owner is offered a matching term. If a home is sitting on a short-term lease from the AB 252 era, the rent can only move under the annual CPI-based cap, which AB 754 also revised, setting a floor of 3 percent and a ceiling of 7.5 percent, with any cost-of-living jump above 5 percent cut in half before it is applied.
There is also a built-in brake on flipping. If a home resells within five years, the reset cap drops from 25 percent to 15 percent, which makes rapid resale a less useful strategy for anyone hoping to reset rent repeatedly on the same berth.
One transitional detail is worth flagging for anyone reading this in real time. Between July 1, 2025 and July 1, 2026, the law let marinas apply the new reset formula to in-place transfers even if a qualifying 10-year lease was not already in place, a one-year bridge meant to smooth the handoff from the old rules to the new ones. That window closed at the start of this past July. Any transfer happening now falls under the standard rule: a qualifying long-term lease has to already exist, or have been offered, before a marina can reset rent at the time of sale.
Floating homes are generally assessed as real property for tax purposes in Marin, though the exact classification can vary by structure and is worth confirming directly with the Marin County Assessor's office before you assume how a specific home will be taxed or financed.
What This Means Before You Write an Offer
For a buyer comparing a Sausalito floating home to a land-based property in Mill Valley, Tiburon, or elsewhere in Marin, the usual comparison stops at sale price and estimated carrying costs. That comparison now needs one more step on the water. Before you settle on an offer number, ask three things: what the current berth rent actually is, whether the existing lease already runs 10 years or longer, and whether the marina intends to offer you a similarly long lease as the incoming owner. If all three point toward an in-place transfer under AB 754, your offer price is not just a negotiation over the home. It is a negotiation over your rent ceiling for years afterward, and the two numbers deserve to be worked out together rather than in sequence.
A Few Questions Worth Asking
Does AB 754 apply at every Sausalito marina? The law covers floating home marinas throughout Marin County, but individual lease terms, current rents, and whether a given home already carries a qualifying 10-year lease all vary by dock. Confirm the specifics with the marina directly.
What if the home I'm considering is on a short-term lease? Then the vacancy decontrol provision does not apply, and rent can only move under the annual CPI-based cap regardless of what happens at sale.
Is a floating home actually less expensive than a comparable land-based home in Sausalito? Purchase prices for floating homes often run lower than land-based equivalents, but berth fees, specialized insurance, and now a rent formula tied to sale price all add ongoing costs that need to be modeled on their own, not assumed away by a lower sticker price.
If you are weighing a floating home against the rest of what Marin has to offer, or trying to work out what a specific dock's numbers actually mean for your budget, Rick van der Wal can help you run the math before you write the offer, not after. Let's Connect.
