I’m planning to take a trip this winter to Gonzaga Bay down in Baja to visit friends. . . .
I look forward to your suggestions.
I have been traveling in Baja California and Baja California Sur since the early 1960's. Although I now live in mainland Mexico, I still spend at least a month each year in Baja.
These are my thoughts on preparation/gear to carry for your trip to Gonzaga Bay:
General Vehicle Condition
Handle any deferred maintenance before you leave, oil and fluid changes up to date, all fluids topped off.
Inspect steering, suspension, brakes, etc.
All bolts tight, no leaks.
Fresh wiper blades, etc.
Tires
Baja is hard on tires. Be sure your tires are in good shape, not worn, out of balance, previously patched, etc.
Carry a full size spare plus a tire tube. You will probably never need the tube, but if you wreck two tires the tube may be your band-aid that gets you back to California without having to buy a mismatched tire in Mexico.
Carry tire deflators, a pressure gauge and a means to air up. (I use a Viair 400 series compressor.)
Tire Plug Kit (I use Safety Seal).
Valve stem repair kit (I carry a Colby emergency valve).
Tire changing tools/jack
Leather gloves
Full size shovel (not a folding trenching tool).
Recovery
Getting stuck in silt or sand is more likely than getting hung up on a rock. Bear in mind that you have to get your jeep back to California if you are tempted to engage in any technical rock crawling in Baja and that it is a long, expensive tow back to the border.
Carry a tow strap, kinetic rope and shackles (soft, hard or both) and be sure you know where all the attachments points are before you leave home.
Traction boards can be helpful but are bulky. Lengths of scrap carpet or asphalt shingles can serve the same purpose.
Tools
Basic hand tools - just the basics not an entire "mechanic's kit."
Common wrench and socket sizes
Crescent wrench
Screwdrivers
Pliers
Hammer
Knife
Flashlight(s)
Spare Parts
DNS (does not start) parts - crank and cam position sensors, extra coil pack and spark plug, etc.
Radiator repair kit (fiberglass mesh, JB weld, extra hose, hose tape, clamps, etc.)
Spare serpentine belt/engine belts
Assorted nuts, bolts, baling wire, electrical wire and connectors, duct tape, zip ties, fuses
U-joints
Glues and sealants - Superglue, JB Weld, Gorilla glue, etc.
Fluids - Don't go overboard. A quart of oil and filter, 1 quart transmission fluid, and maybe a quart of gear oil. You don't need coolant - water will work until you get home - your emergency water is for drinking and your cooling system.
Remember that your goal is to get back to pavement or to the next town, not to rebuild your jeep in the field - carry spares and tools appropriate for that purpose.
If you get stuck someplace in need of parts, don't forget that Amazon and Amazon.mx deliver to every city and town in Mexico.
Mapping
GPS and extra batteries
Paper map and compass.
Notebook, pen and pencil
Communications
Cellphone and extra battery/charging cord
CB, GMRS or ham radio (whatever your travel companions use)
Personal locator device such as Garmin Inreach
Spanish/English translator and/or paper dictionary. Although there are many gringos in Baja and many Mexicans in Baja speak a bit of English, you will be in Mexico and the language is Spanish. Attempts at Spanish, even if feeble, will be appreciated.
Hygiene
Toilet paper
Sunscreen
Personal care items
Safety
First Aid Kit (a real one, not just band aids)
Tylenol, Imodium, Pepto Bismol
Extra glasses/sunglasses
Shelter
tarp, rope, stakes, blanket, bungies
Survival
Extra water
Extra fuel
Emergency Food
Documents
Passport or Passport Card
FMM - Do not forget to pay for and have your Tourist FMM stamped at the INM desk at the border. Mexican customs will try to waive you through - it is your responsibility to ask for Immigration and obtain your FMM even if Customs tries to tell you it is not necessary. [See:
https://www.mexperience.com/your-mexican-tourist-permit-fmm/]
Permission from lienholder (if any) to take vehicle to Mexico
Mexican liability Insurance (I use Baja Bound/Chubb)
Copies of passport, drivers license, etc. (NOT color copies - considered "counterfeit" or "forgeries" in Mexico, B&W only for copies of personal ID or government documents)
Copies of Vehicle Title and Registration
Money
Carry pesos. You can get a few at a cambio before you cross the border, but the cheapest and easiest way is at any bank ATM once in Mexico. However, always decline the ATM's offer of a conversion rate because your home bank's rate will always be better.
Resource in San Felipe:
If you get the chance, try to meet my friend Bruce Kobus, also known as "Baja Bruce," a Canadian jeeper who winters at Kiki's RV Park in San Felipe. Although Bruce's usual beachfront spot at Kiki's was decimated by the recent hurricane, he is usually there between the first of November and May and Kiki should know where Bruce is staying if not at Kiki's. Bruce is a good guy to know if you find yourself in trouble in or around San Felipe, and a good guy to know in general.
Espero que esta información le sea útil.
Diviértete y mantente seguro.