Repelling unwanted guests

Nature is at its best when voyaging. Wherever you go there are new experiences to remember: dolphins playing under the bow, albatrosses swooping through the loom of the running lights and big brown bears lumbering along a remote Alaskan beach.

Sometimes nature can be unpredictable, though, especially if your guard is down and you haven’t taken precautions against creatures boarding you. Good planning and a little work will prevent many annoying experiences, no matter where you are voyaging.

During the last 50 years that voyaging has been popular, swimming mammals, such as seals, sea lions, muskrats, mink and otters have been relatively scarce in harbors and anchorages around the world. Lately, the concerted efforts of wildlife supporters and governments and changes of fashion around the world have created a population explosion that can affect cruisers.

Mink ranchers with no place to sell their harvested pelts have let their animals go wild. Now, temperate zone anchorages may have mink swimming around looking for food. A hungry mink can overcome any pet very quickly. Make sure mascots are kept below or watched over whenever there is a risk of a mink boarding. Placing a “mink guard” on the anchor chain and stowing the boarding ladder will help keep aggressive mammals swimming on by.

Inflatables and hard dinghies should be hoisted to the sheer line or onboard at night so that curious sea lions won’t hop in for a rest and maybe break or flip away a precious oar or paddle. (We were in the habit of leaving our nice wooden oars inside our Zodiac as it lay moored alongside our sailboat at night. One night in the Galapagos we heard a splash and a thud and in the morning the oar was gone!)

Rats and mice have plagued sea-goers for millennia and show no sign of letting up anytime soon. The best defense against long-tailed visitors is to stay away from marinas and piers infested with them. Other voyagers are the best source of up to date information on this score.Guarding against rats

Rat guards on mooring lines are only useful if no other vessel or pier is within three or four feet, since rats can easily jump that far. “Electronic cats” (high-frequency sound generators) work very well in keeping rats away. However, they cannot be used if any desirable pets are onboard or within 100 feet, as the same ultrasound frequencies that hurt rodents’ ears will also torment dogs and even cats.

Keeping pet food and other eatables off the open deck is a must. After sundown, cockpit gatherings can easily produce crumbs and scraps that can be overlooked in cleaning up in the dark - but rats will find them!

If a rat or mouse does get down below, do not try to poison it or try to kill it with a boat hook or other weapon. One voyaging friend took swipes at a rat with a boat hook and never connected with the rat, but he did break the screen on his radar with the other end. If the rat crawls under a tank or some other unreachable place and dies, the smell of decaying rat won’t be fun.

Here are two methods that have worked for us:

Buy rosin-coated boards sold in hardware stores and janitorial supply firms. Make sure the boards are tied securely and placed in a spot not easily stepped on by a crewmember. If a rat or mouse should get its feet stuck in the sticky rosin, scoop the board and rat into a fish-landing net, quickly twist the net, untie the board or cut it loose, and promptly carry all on deck and dispose of the rat by any suitable means.

The second way is probably the best for anyone squeamish about tussling with live rodents, even if they are wrapped up in a landing net and stuck to a rosin board! Stow all loose gear below or ashore to clear the deck. Cover dorade vents and other possible places for a rat to hide. After dark, find a good book and a cozy corner down below with a good view of the companionway ladder. Place small pieces of cheese or other tiny goodies on the rungs of the ladder and out in the cockpit. Prop up the hatch board with a stick that has a light line tied to it and lead the line back to your cozy spot. Close the companionway hatch as much as you can with the board propped up.

Then, in the quiet, start reading your book and listen for the sound of the rat’s feet on the cockpit sole. It might take a couple of hours, but he will surely come out of his hiding place to look for food and will find your trail up the ladder. Once he has climbed into the cockpit, pull the stick and drop the hatch board, effectively keeping him out from down below. Make as much noise as you can to frighten the rat and make him jump overboard!

If at daybreak you know he is still aboard by the patter of his feet on deck, prepare yourself with air horns and other noisemakers and spray cans or trigger sprayers of anything with a strong odor. Bang on the hatch and yell to make the rat go to another part of the boat. Open the hatch and jump out in the cockpit as fast as you can. Close the hatch behind you. Then start at one end of the boat and make noises, spray into hiding holes and poke around with a boathook, driving the animal to the other end, hoping he’ll jump overboard. If he still eludes you and stays aboard, call a friend with a mean cat!Other pests

In cold waters, little fish like to snuggle up against the hulls of heated vessels, especially boats with un-insulated fiberglass or metal hulls. If they are right by a head intake, they can easily be swept into the through-hull opening, pumped up the line and lodged in the intake port, effectively stopping action. Nobody likes taking the head apart, even the intake side, especially just before bedtime.

After disassembling the intake valve a few times and finding a little fish badly mashed inside, we discovered a solution to this problem: Just before using the head, we jiggle the handle quickly. The vibration transmitted down the intake hose seems to scare the small fry away.

Mosquitoes come swarming aboard at just the perfect time to sit in the cockpit and enjoy the brilliant sunset colors and cool temperatures. Citronella candles and lamps, placed strategically upwind on the cockpit coaming, on a binnacle table and under the dodger, will send all but the most aggressive insects away. If 220-V power is available, the plug-in insect repellents, sold outside the United States, work very well. The power draw is small, so a few hours’ use a night can be supported by the battery bank.

Inspect tank vent holes and other small openings frequently to make sure wasps or other insects are not building nests in them. When leaving the boat for more than a few days, be sure to place tape over all small openings.

Maybe someday some instrument as magical as a GPS is for navigation will be discovered that will keep unwanted creatures away, but not too far away, without disturbing pets and people. Until then, everyone must fend for themselves as best they can. This challenge is just one of the joys of the voyaging life. n

Knick and Lyn Pyles, who spend much of their voyaging in South America, are home-based in Point Roberts, Wash.

By Ocean Navigator