As boaters pass by Johnny Carson’s pride and joy, Serengeti, a 139-foot Westport, sitting on her Marina del Rey end-tie looking immaculate, many might take a guess at how much the luxury power yacht must have cost the late talk show legend.

For other boaters, the burning question isn’t about the sticker price, but what it costs to maintain that thing. For it’s the daily, weekly and monthly upkeep in boating and the reality of where to park the new toy that aren’t mentioned in the brochure.

“There’s a lot of different elements to it,” said Brian Spevack of Spevack Yacht Maintenance, which provides the exterior cleaning for Serengeti, among many other yachts in the Marina.

“The annual engine maintenance, the bottom cleaning service (once a month), the topsides — washdowns, waxing and, if you entertain a lot, the interior cleaning — it really adds up.”

For Spevack to clean the interior of a 40-foot boat, it would cost $50 and for the exterior, between $1.30 and $1.75 per foot.

These prices are based on either a weekly or biweekly visit structure. Spevack doesn’t do monthly washdowns, as he feels they are not practical for either party.

Two-week periods are the proper interval, according to this company. Under this pricing, a medium sized boat (40 feet) would cost $240 per month to keep clean, before bottom cleaning.

Typical costs for monthly bottom cleaning are about $1.25 per foot, bringing the cleaning tally for the average boat up to $290 per month.

Although Spevack offers a high-end service and admits to being more expensive than his competitors, his prices paint the basic picture.

After the dirt is washed away and a voyage is on the horizon, it’s the price of fuel that will be the next consideration.

A few short years ago, gassing up the powerboat for a middle-class family to take a jaunt over to Avalon was no big deal, but these days such an outing could cost thousands when food, mooring costs and fuel are all factored in.

“Catalina and back is $450,” said Larry Glass who just recently sold his 35-footer with twin 454 V-drives that burns about 30 gallons an hour.

“I said last year when [fuel] reached $2.50, if it hits $3 a gallon I’m selling.

“If you do five trips to the island, it kills ya. I used to go to Catalina and back for one hundred and fifty bucks — it wasn’t so bad.”

For fishermen who sometimes need to get places in a hurry, a trip is far more costly than it used to be.

“I was on a boat recently that was running three 250-horsepower outboards,” said competitive fisherman Dave Kirby. “Filling up the tanks and traveling 120 miles a day cost us roughly a little under $2,000 a day. Granted that was running them at 70 miles an hour.”

Now all of these figures are only relevant and of any interest if there is a place to park the boat in the first place and, according to Marina del Rey dockmasters, there simply are no spots available.

When asked for vacancies for a 30-foot boat or a 40-foot boat, dockmasters in the area indicated that there were no slips to be had.

“I have had people on a waiting list since 2004,” one of them said.

Another dockmaster spoke of a four-to-five-year list for 40-foot vessels at a cost of $19 per foot or $760 a month.

The good news for would-be boaters is that sometime around the beginning of the new year, the Esprit Marina, a new facility that is currently under construction, will open and create a bit more supply for the inordinate demand of the present situation.

Four hundred new slips will most certainly alter the dynamics of the space availability within the marina. Boats will begin to shuffle around and it’s quite plausible that many of the marinas will begin to once again have spots open.

But if it’s Serengeti you’re after, rumor has it she’s for sale and the monthly nut is not too bad.

To keep her looking shiny it should be somewhere around $500 per month, the slip fee is maybe between $2,000 and $3,000, and fuel for a weekend voyage to Catalina is in the vicinity of $2,200 round trip.

Throw in a captain and a cook and it all looks doable for under $10K a month.