Hordes of cruise passengers at ports. Also, exploding manhole covers in Rio de Janeiro.

Dear Globetrotter:

Welcome to the 427th issue of your monthly overseas travel magazine.

I welcome your comments and observations on this first topic.

Currently, excluding river cruisers and expedition ships, there are 45 cruise ships sailing the seas and oceans. Three of them are “mega cruise ships”: Royal Caribbean International’s Allure of the Seas and Oasis of the Seas and Norwegian Cruise Line’s Norwegian Epic. These megaships are longer, with more decks, more public space and more staterooms.

For most standard, oceangoing cruise ships, the normal passenger capacity is about 3,000 to 3,500, with a maximum (if, ever, every bed were filled) of about 4,000. The three megaships carry, at normal capacity, 4,100 to 5,400 passengers, with a maximum of about 6,300.

Cruising has jumped in popularity over the last decade and the impact is starting to be felt at certain destinations. Fifteen-million passengers cruised in 2010, and, even with 12 new ships added to the world fleet just in 2010, demand continues to exceed available cabin space. Most ships are running at full capacity.

There are 26 new ships currently being built, including four megaships, all scheduled to launch by 2015.

From recent online polls of 2,400-plus US residents taken every couple of years, the Cruise Line Industry Association finds that the most popular cruise destinations are the Caribbean (over 40%); Alaska as well as the Bahamas (more like 25% each); Hawaii; the Mediterranean/Greek islands/Turkey; Bermuda; Europe; the Panama Canal, and Mexico’s west coast.

Even though some destination ports have not been able to upgrade their facilities to allow megaships to dock, the increase in the number of standard-size ships is so great, it’s common to find multiple cruise ships docked at the same port on the same day. At the port of Barcelona, Spain, on March 4 this year, seven ships were docked with 27,200 passengers. As I write this, the same port was booked for nine cruise ships, carrying a total of 31,000 passengers, on Aug. 20, 2011.

The influx of tourists disembarking for their day tours is overwhelming the existing transit systems in many places. Islands are particularly stressed because the numbers of taxis, buses and trams are limited.

In Bermuda, it was announced this April that during morning “rush hours” the dispatcher at the western dockyard would begin restricting the number of tourists allowed on each public bus, in order to leave room for island residents farther down the line trying to get to work. Some visitors taking the bus into Hamilton may experience delays.

(As an alternative, you can take a fast ferry directly from the dockyard to Hamilton; it takes about 20 minutes. A one-way ticket costs $4.50 adult; one- to seven-day passes cost $12 to $45.)

Hordes of cruise day-trippers also clog restaurants and cause long lines at sightseeing places. Venice, Italy, is struggling to handle the floods of cruisers. In 1999 fewer than 100,000 cruise passengers visited Venice, while in 2010 there were more than 1.6 million.

Which places have you found to be particularly affected by cruise crowds (and when were you there)? Share your observations. What advice can you offer to improve a visit? Write to Overcrowded Ports, c/o ITN, 2116 28th St., Sacramento, CA 95818, or e-mail editor@intltravelnews.com.

Watch your step in Rio. An aging system of natural gas lines and electrical transformers under the streets of Rio de Janeiro, Brazil, is resulting in explosions that send manhole covers sky high.

It’s been going on for several years, but the problem has escalated in 2011, with more than 60 explosions from January to July. Dozens of people have been injured, and damage to vehicles and property has cost thousands of dollars.

The utilities system in the underground tunnels is over 60 years old, and sparks from short circuits are igniting gas from leaking lines. The public prosecutor’s office is suing the power company to force them to speed up repairs and replacements. The Rio de Janeiro Tramway, Light & Power Company says it is fixing the faulty electrical junction boxes as quickly as it can and that it will cost about 88 million reals ($56 million). The local gas company is CEG.

A judge recently ruled that the power company must pay 100,000 reals ($64,000) for each of any subsequent explosions.

The power company’s president said, in April, that 130 manhole covers showed signs of potentially exploding, but the public prosecutor estimated that 4,000 manhole covers were candidates for becoming projectiles and that they have “turned the city’s streets and avenues into veritable minefields.”

Rio is hosting soccer’s World Cup in 2014 and the Summer Olympics in 2016.

Here are two organizations whose informative websites catalog where political crises and natural disasters have occurred recently and the effects they have had.

• AlertNet, a “free humanitarian news service… covering crises worldwide,” is run by the Thomson Reuters Foundation.

On the site, you can click on news headlines for details of breaking news. You also can select a specific country and read overviews on different aspects of life there; subheads include “Country Snapshot,” giving a brief rundown of existing national tensions and concerns, “Government,” summarizing the political structure, “Economy,” “History,” etc.

• Relief Web, administered by the United Nations Office for the Coordination of Humanitarian Affairs (OCHA), set up www.reliefweb.int specifically to provide information for non-governmental organizations (NGOs) and relief agencies around the world responding to disasters.

The homepage posts news stories and lists problem areas, and you can also drill down by country. Maps are included. The information is constantly updated.

In some cases, you can download informative UN or primary relief agency reports from personnel on the ground. These can be more informative than the general media, which doesn’t have the time or space to list specific towns, roads, bridges, etc., that have been affected.

In response to an information request that we printed from Barbara Glavish of Incline Village, Nevada, we presented lots of advice and anecdotes from travelers in our May and June ’11 issues.

Barbara recently wrote, “I’d like to thank the many subscribers who wrote in with tips for managing liquids and gels with carry-on only. There were many really useful ideas, and I’m amazed at the ingenuity of some of these travelers.

“One subscriber said that she had stopped carrying insect repellent. Well, she’ll need it if she ever goes walking in the countryside of Slovakia or Hungary during the summer months as I did. There were clouds of mosquitoes.

“I also appreciate knowing about the websites that Dann Halverson noted. Thank you, all.”

Judy Serie Nagy of San Jose, California, wrote, “I find it amusing lately to read my glossy travel mags (I subscribe to all but the dumbest ones), and I’m beginning to sneer at them — the dopey models in their designer apparel, the articles that ramble on and on but really don’t have much information. I enjoy leafing through them, but when ITN arrives, it gets read RIGHT NOW.”

Linda Ollis Fache of Omaha, Nebraska, wrote, “My husband and I love ITN. It has the most practical tips and honest reviews of any of the travel publications, and we’ve learned from its advice!”

Sharon Hess of South Lake Tahoe, California, wrote to us, “I would like to share ITN with a friend (address enclosed). Would you please send a free sample copy to her?”

Sharon continued: “I’ve been an ITN subscriber for several years and really enjoy this monthly publication. I usually read it cover to cover as soon as it arrives. I subscribed based on a recommendation of one of your other subscribers and have never been disappointed. I might give up another travel publication, but you have me as a subscriber for life. Thanks and keep up the good work!”

All the encouragement is appreciated. More important are your travel reports and photos for all to see. Keep ’em coming!