In Panama's rainy season, from roughly May to November, rain is what sinks boats at the dock and on moorings. A tropical downpour can fill a cockpit faster than a tired pump can empty it. Keep drains clear, run two pumps on a healthy battery, test the float switches and have someone check the boat after every big storm.
Why boats sink at the dock in Panama
Boats sink at the dock more often than underway. A US Coast Guard Auxiliary article published by Waterway Guide puts dock sinkings at about four times the number underway, and names failed through-hull fittings and rainwater from clogged drains as the two biggest causes. Panama has no snow, but it has rain that does the same job.
The pattern is nearly always the same:
- Leaves, dirt or a lost cover block the cockpit scuppers.
- Heavy rain fills the cockpit, and water finds its way below through hatches, lockers and seals.
- The bilge pump runs until the battery is flat, or the float switch jams with debris.
- Water rises to the through-hulls or the stern sinks low enough for the scuppers to flood back in.
Open boats on moorings are most exposed, because nobody sees the water rise.
How much rain to plan for
Panama's weather institute, IMHPA, describes the rainy season as starting in the Pacific west at the end of April, with September and October usually the wettest months. Afternoon thunderstorms bring heavy rain, gusts and lightning on both coasts, and La Niña years bring more of it. Bocas del Toro and the Caribbean coast can see heavy rain in any month.
IMHPA issues weather warnings, and SINAPROC, the civil protection agency, issues alerts for heavy rain. When either is in force, assume your boat will take on rainwater and check it. The Panama boating seasons guide explains the pattern by coast.
A pump setup that copes
- Two pumps. A primary automatic pump low in the bilge and a larger second pump mounted higher, with its own float switch.
- A high-water alarm. An audible alarm, or a remote alert if your boat has connectivity, tells someone the primary pump is losing.
- Real capacity. A pump's rating is measured with no lift and no hose. Height, hose length and voltage drop cut what it actually moves, so size up.
- Clean wiring. Use tinned wire, sealed connections above the bilge water and a fuse at the battery. Corroded pump wiring is a common failure in Panama's humidity.
- Battery. The pumps should draw from a healthy battery that is kept charged by shore power or solar. A pump on a flat battery does nothing.
- Strainer and check valve. Keep the strainer clean and make sure the discharge cannot siphon back in.
For batteries and charging, see electrical systems and batteries in constant heat.
Drains, covers and where water gets in
Keeping rain out is cheaper than pumping it.
- Clear scuppers and cockpit drains every visit and after every storm.
- Check that scupper flaps close and are not cracked by the sun.
- Use a cover that sheds water, with no pockets where rain pools and pulls it down.
- Reseal hatches, windows and deck fittings in the dry season, before the rains find the leaks.
- Check through-hulls, hose clamps and stern glands while you are at it; they are the other half of dock sinkings.
On the Pacific side, tides of 4 to 6 m mean lines on a fixed structure must allow for the full range, or a boat can hang at low water. Most marina berths are floating docks, but check yours.
If you find water in the boat
Do not assume it is rain. Taste a drop: fresh water points to rain or a tank, salt water to a through-hull, hose, stern gland or a crack. Then work in order:
- Check the pumps are running and the battery is holding voltage.
- Look at the through-hulls, hoses and clamps below the waterline, then the stern gland or shaft seal.
- Use the manual pump or a bucket if the automatic pump is losing.
- Call the marina office for help, and SENAN on VHF 16 if the boat is at risk of sinking with people aboard.
Once the boat is dry, find and fix the source before you leave it again. A boat that took on water once usually does it again.
If you are not there when it rains
Many owners in Panama live abroad or in the city, an hour from the boat. Arrange cover before May:
- Agree with the marina or a caretaker who goes aboard after heavy rain, and what they check.
- Ask for a photo of the bilge and the battery voltage each time.
- Leave clear instructions on where the manual pump and the battery switch are.
- Put the boat on the hard for the wettest months if it is a small open boat that will not be used.
Include the pump test in your rainy-season prep and write each check in the maintenance log.
Your practical starting checklist
- Clear every scupper and cockpit drain, and check the flaps close.
- Lift each float switch by hand and confirm the pump runs and discharges overboard.
- Fit a second, higher pump with its own switch and a high-water alarm.
- Check the pump battery, wiring and fuse; replace any corroded connection.
- Inspect through-hulls, hose clamps and seals below the waterline.
- Arrange for someone to go aboard after every heavy rain while you are away.
Frequently asked questions
Do boats really sink from rain in Panama?
Yes. Heavy tropical rain fills cockpits quickly, and when drains clog or a pump's battery goes flat, boats sink at the dock or on a mooring. Rain is one of the two main causes of dock sinkings.
How big should my bilge pump be?
Larger than the label suggests you need, because ratings are measured with no lift or hose. Fit a second, higher pump and an alarm rather than relying on one big pump.
How often should I test my bilge pumps?
Every visit, by lifting the float switch, and after every heavy rain. Do a full test of pumps, wiring and alarm before May.
¿Cómo evito que mi lancha se hunda por la lluvia?
Mantenga limpios los imbornales, instale dos bombas de achique con flotador y una alarma de nivel alto, cuide la batería y pida a alguien que revise la lancha después de cada aguacero.
The next question to answer
The pillar guide for heat, growth and rain. Read Boat maintenance in Panama's tropics.
Every Panama maintenance guide in one place. Read Maintenance in the tropics.
Covers, drainage, lightning and mould before May. Read Rainy-season prep.
Same topic in Florida: coming from the US? Compare Bilge Pump Checks and Maintenance.
Official resources
Use the relevant Panamanian authority for current requirements and fees. These resources are the next place to check; a practical recommendation is not an agency determination.
- Instituto de Meteorología e Hidrología de Panamá (IMHPA): forecasts and warnings ↗
- SINAPROC: civil protection alerts ↗
- Waterway Guide (secondary): Boats sinking at the dock is 4x more than underway, USCG Auxiliary, Feb 2023 ↗