I would only be concerned about the water you drank. If you have a (screen strainer) on the inlet to your boat fresh water pump, that will protect your pump from debris.
If you are trying to prevent drinking water bacterial contamination read this...
https://en.wikipedia.org/wiki/Portable_water_purification
I have 160 gal of fresh water on my boat. I might drink a QUART a day, beyond my boiled coffee water, my purchased ice, beer, beverages, and bottled water.
I use anti-bacterial soaps for dishes, my feet, bootie, swim suits, etc.
The only filter that gets it
ALL is Reverse Osmosis (RO) kind like they use on cruise lines. RO can change salt water to fresh water and removes even, minerals, taste and typhoid. Most commercial bottled waters are not chlorinated and are RO water. Read the labels.
If you sail to the "islands", water is more expensive than diesel or if you live in CA water shortage times. So many cruisers install a RO system on their boats. One boat I considered when I was shopping had a 8 gal/hr 12VDC system which only cost new $5k, but you can buy a survival type hand pump RO to make 1 quart in 30 minutes building arm muscles. Hmmmmm 30 min exercise to make my daily on board drinking needs.
You can buy purifying drops/tablets like military or back packers use (makes fresh water safe to drink). I have a $6 bottle of tablets and mylar solar type still, in my emergency/survival box.
My spring time boat clean, fix, check, and make ready
LIST has fresh water tank dump/refresh on it. I drain both my tanks to 50%, add a half cup of laundry bleach to each tank ( 1oz to 20 gal), top off each tank, drink a beer and wait 30 min, drain both tanks empty and inspect/clean the pump strainer.
Refill with marina (city tested) water using a white RV type hose to prevent rubber hose taste.
Last point and to your question...
My Hunter's tank vents are cleverly done thru a vertical stainless grab pole to the deck near the mast. Like you, i wondered about salt water sprays, insects blocks/intrusion. They put the vent under the FRP deck that covers my lines from rigging to cockpit. They installed an elbow pointing aft with stainless mesh bug screen over it. It would take a 10 foot wave over the bow to perhaps get about a teaspoon of salt water in my vent line ( rare and i don't worry I still have beer on board.:dance
Let fresh water be no worry and enjoy the sail....
Jim...
