Taking a look at this page from the Oxford Advanced Learner’s Dictionary online, one also discovers that Americans don’t usually use the expression going to the seaside (the OALD marks it as “especially British English”), preferring seaside as a premodifier instead. (This is also supported by data from both the COCA and BNC.)
On the same page one can find a link to the phrase whelk stall. As you would expect, the word whelk can be pronounced both welk and hwelk. As far as this latter pronunciation goes, LPD (p.897) correctly states that “an initial hw in the sense ‘shellfish’ is not supported by the etymology”.
This statement is backed up by my Oxford Dictionary of English (2nd edition revised, 2005; p.2004), which distinguishes between the mollusc (1) and an archaic term for a pimple (2):
“whelk1 ► noun a predatory marine mollusc with a heavy pointed spiral shell, some kinds of which are edible [...].
- ORIGIN Old English wioloc, weoloc, of unknown origin; the spelling with wh- was perhaps influenced by WHELK2.
whelk2 ► noun archaic a pimple.
- ORIGIN Old English hwylca, related to hwelian ‘suppurate’. “