Lighthouse architects faced a number of challenges. They had to design structures that could withstand exposure to high winds, salt water, snow and ice. Island lighthouses were constructed by local builders using locally available materials whenever possible.
Consideration had to be given to the placement of the lighthouses in more ways than one. They had to be placed to warn of headlands and hidden reefs as well as at harbour entrances. Another major factor to be taken into consideration was the height of the site above sea level and the distance the light had to shine to warn mariners. A report in the Journal of the House of Assembly stated the following concerning the construction of Point Prim Lighthouse:
“That the elevation of the proposed Lighthouse should not be
less than eighty feet (24.3 m) above the level of the sea. That the
site on which the lighthouse itself should be placed, is about twenty
feet (6.1 m) above the sea. That the building itself, therefore, will
require to be about sixty feet (18.2 m) high. That this elevation
will place the lights at about seventy-five feet (22.8 m) above the
sea, which will render them visible on the horizon at a distance of
eleven miles and a half (18.5 km). That a person standing on the deck
of a vessel approaching the lighthouse, having his eye raised twenty
feet (6.1 m) above the sea, will be able to observe them at about
seventeen miles and a half (28.1 km), which appears sufficient for
ordinary occasions; and in emergency, by sending aloft, a sight of
the light might be attained at a distance of twenty miles (32.1 km).”
Point Prim was the first Prince Edward Island lighthouse.